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If you’re drowning in zucchini, an easy zucchini gratin recipe is the perfect way to use up a good amount. This low carb cheesy zucchini casserole requires three medium zucchini in a 1 1/2 quart casserole dish, but you can easily double (or even triple!) the recipe to make more in a larger pan!
As we head into August, I know I’m not the only one with more zucchini than I know what to do with. Anyone with a garden will say that right now!
I keep meaning to start a garden, but never have the time. One of these years I’ll take the plunge.
For now, despite no garden, I still have a zucchini problem. It’s my own fault, too. I just couldn’t resist buying way too much at the farmers’ market.
It’s a good thing my family loves zucchini as much as I do. All the more reason to make cheesy zucchini au gratin, right?
The only thing is, I struggled with the name for this dish. Cheesy zucchini gratin? Low carb zucchini casserole? Healthy zucchini bake? I couldn’t decide, so I’m using the names interchangeably.
An Easy Zucchini Casserole Recipe for Zucchini Week
Fortunately, it’s Zucchini Week here at Wholesome Yum, so I have lots of ways to use up all my zucchini! So far, I’ve made zucchini pizza bites, fried zucchini & squash, and zucchini noodle salad with bacon and tomatoes. I can’t even decide which one I like best.
My whole family is loving Zucchini Week. There aren’t many foods that are awesome enough to want to eat every day for a week. This is one of the few.
Zucchini is naturally low carb, keto friendly, gluten-free, and everyone loves it even if they aren’t following any of those special diets. In the middle of the summer, give me all the zucchini!
Low carb zucchini gratin is yet another way I’m using zucchini this week. With a delicious creamy brie sauce, cheesy Swiss Gruyere topping, Italian seasoning, and summer zucchini (of course!), you can’t go wrong. It’s the ultimate comfort food.
Cheesy low carb casseroles like this one are my favorite kind. If you’re a fan of them too, you’ll want to check out my brussels sprouts casserole au gratin, pesto chicken bake and low carb cauliflower casserole. This easy broccoli cheese soup is one of the most popular! Can’t forget to add this cheesy zucchini casserole to the list!
Ways To Make Low Carb Zucchini Casserole
There are multiple ways that people make baked zucchini casserole recipes. Many of them shred the zucchini first, or they cook it in some way separately, to get rid of the moisture.
I’d like to try a shredded zucchini casserole sometime, but I thought a sliced zucchini gratin was actually a much faster way to make an easy zucchini casserole. And you probably know by now – I am all about easy!
That’s why I think you’re going to love how quick it is to prepare this cheesy zucchini gratin bake. The active prep time is only then minutes!
The “hardest” part is impatiently waiting for the sliced zucchini to drain in the beginning. (Patience is not my strong suit. I commend anyone that’s good at it.) But, you can go off and do something else while this is happening.
Ingredients for Easy Zucchini Gratin
This low carb zucchini gratin recipe uses common ingredients that I often have around. During the summer months, it’s pretty typical for me to create easy zucchini recipes on a whim. And, the most common themes are cheese (lots of cheese!) and random ingredients I find in the fridge. This was one of those!
The ingredients needed are zucchini (obviously!), sea salt, black pepper, brie cheese, heavy cream, almond milk, butter, garlic, sharp shredded cheese, and Italian seasoning. Okay, so that list is not as short as my five-ingredient recipes. But, these are all simple ingredients you can find at your local grocery store.
I recommend using brie in the sauce as written, because it creates a super creamy consistency. It thickens it very nicely, too!
As for the cheesy zucchini casserole topping, feel free to swap any shredded cheese you like. I used a blend of Swiss and Gruyere for lots of depth and flavor. Cheddar would be delicious, too!
The Key to the Best Zucchini Casserole Recipe
The key to the best zucchini casserole recipe is making sure that it isn’t too watery. Zucchini is a very “wet” vegetable, and baking it in a casserole dish releases a lot of moisture. This is even more true when you are not using a starch, like flour. So, it’s important to take that into account when making gluten-free zucchini casserole recipes.
This is why the draining step is so important. Please, please don’t skip it! It prevents the low carb zucchini casserole from becoming a watery mess. Sprinkling the slices with salt first helps them drain better, so that is why we do that first.
While the zucchini drains over the sink, you can use the passive time to make your main dish. I think it goes very well with pesto stuffed chicken. Both are filled with Italian flavors. (Or, get out of the kitchen and spend some time outside!)
Once the zucchini is done draining, the rest of the steps are quick and easy. Just ten minutes prep, remember?
How To Make Zucchini Casserole
Preheat the oven to 400 while you prepare the zucchini casserole. Arrange the zucchini slices in overlapping rows in a small casserole dish, and season them with black pepper. I like to use a stoneware dish like this one.
Next, heat the brie, cream, milk, butter, and garlic in a small saucepan, until everything is nice and smooth. Here is the cheese sauce for your zucchini casserole! Don’t be surprised if it’s a little thin – it will thicken more in the oven later.
Pour the sauce over the zucchini, and top with plenty of shredded cheese. (In case you couldn’t tell, this is the ultimate cheese lover’s zucchini side dish!)
Don’t forget the Italian seasoning on top. If you have other herbs or spices around, feel free to use those instead. This zucchini gratin recipe is quite versatile! In fact, if you happen to make this dish later on in the fall, it would be delicious with some fresh rosemary, too.
Stick your cheesy zucchini casserole into the oven for about half an hour, until it’s golden brown. You’ll know it’s done when the zucchini is soft, the cheese is browned, and the sauce is thick.
If the cheese browns but the sauce is too watery for some reason, you can still fix it. Cover the top (to prevent burning the cheese) and lower the oven temperature to 350 degrees. Then, continue baking for another 10 to 20 minutes, until the sauce thickens more.
That’s it – your zucchini au gratin is ready to serve! It’s simple, it’s delicious, and it’s definitely the best zucchini casserole in my book.
Baked Easy Cheesy Zucchini Casserole Recipe (Zucchini Gratin):
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RECIPE CARD
Baked Easy Cheesy Zucchini Casserole Recipe (Zucchini Gratin)
Recipe Video
Click or tap on the image below to play the video. It's the easiest way to learn how to make this recipe!Ingredients
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Instructions
Get RECIPE TIPS in the post above, nutrition info + recipe notes below!
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- Toss the zucchini slices with sea salt. Place into a colander and set over the sink to drain for 45 minutes. Pat dry at the end.
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Preheat the oven to 400 degrees F (204 degrees C).
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In a small 1.5 quart (1.5 L) casserole dish, arrange the zucchini slices in several overlapping rows, sprinkly very lightly with half of shredded cheese between rows. You'll use about 3/4 cup cheese total. Season lightly with black pepper. (They already have salt at this point.)
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Combine the brie, cream, milk, butter, and garlic in a small saucepan. Heat for a few minutes on the stove over low to medium-low heat, stirring frequently, until the cheese melts and the mixture is smooth. If desired, add sea salt to taste. Pour the mixture evenly over the zucchini.
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Sprinkle the remaining 3/4 cup shredded cheese blend on top. Top with Italian seasoning.
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Bake for about 30-35 minutes, until the cheese on top is dark golden brown and the zucchini is soft.
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Recipe Notes
Serving size: 1/6 of entire pan
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Nutrition Information Per Serving
Where does nutrition info come from? Nutrition facts are provided as a courtesy, sourced from the USDA Food Database. You can find individual ingredient carb counts we use in the Low Carb & Keto Food List. Net carb count excludes fiber, erythritol, and allulose, because these do not affect blood sugar in most people. (Learn about net carbs here.) We try to be accurate, but feel free to make your own calculations.
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86 Comments
kazy
Should the rosemary be chopped or should I just throw a few twigs on top before baking?
Wholesome Yum M
Hi Kazy, If you would like to add rosemary, I would remove it from the stem and finely chop it.
Katie B
I was wondering if dehydrating the Zucchini sliced and using them in the casserole would be helpful with the “soggy” or “too runny” comments?
Kind of the box scalloped potato method but way more healthy 🙂
I am going to try it tomorrow (wish me luck).
Wholesome Yum M
Hi Kaite, I’m not sure, I haven’t tried dehydrating the zucchini. Please share with us how it turns out!!
Katie B
It turned out great…I didn’t have enough time to completely dehydrate the zucchini slices but I think it helps the texture. Fabulous recipe, very good pairing of cheeses.
Arielle
I made this for Christmas and it was excellent. I didn’t have brie or heavy cream, so I used some fontina and half & half. I’m looking forward to trying this again with the heavy cream.
Ximena
Great reciepe!!! It came out delicious eventhough I used zucchini and eggplant.
Rhonda Sherlock
This is delicious!
Cathy
I am having to use 10% cream as I don’t have heavy cream. What will it do to the zucchini casserole? Should I modify anything ?
Wholesome Yum M
Hi Cathy, Your casserole may be a little looser, but the recipe will still work fine without any alterations.
Cathy
Made this once and it became my go-to recipe for the rest of the zucchini season! Delicious!
Janet Savoy
I love your recipes..can you recommend recipes that can be prepared in an air fryer.and how to reheat in a microwave?
Wholesome Yum M
Hi Janet, I have several air fryer recipes, including Keto Onion Rings, Chicken Wings, Stuffed Baby Artichokes, Fried Chicken, and Jicama Fries. All of these recipes can be reheated in the air fryer, oven, or microwave.
Janet Savoy
Hello..how do you fix a zucchini casserole recipe thts a little too salty?
Wholesome Yum M
Hi Janet, You can stir in a little extra cooked heavy cream to help with the saltiness.
Joyce
This recipe was great! I really enjoyed it and a great way to make zucchini! Thanks for sharing!!
Valerie Tafat-Johnson
Can you do this in an instant pot?
Wholesome Yum M
Hi Valerie, Sorry, the casserole would be too watery if cooked in an Instant Pot.
Johelen
This is a great recipe and it’s our dinner tonight. Simple and wholesome. The poor rating is because of the overwhelming saturation of ad content. Way too frustrating to swim through it all to get to the back to the recipe twice.
Maya | Wholesome Yum
Hi Johelen, I’m glad you liked the recipe. I only accept ratings for my actual recipes, not the website. 🙂 Ads keep the Wholesome Yum website running and allow me to develop recipes that readers like you can access absolutely free. However, you may be interested in Wholesome Yum Plus, which includes an ad-free version of the website, along with other perks.
tonya sanchez
Can I add a little flour in between my layers like I add to my scallop potatoes, and what effect would it have?
Wholesome Yum M
Hi Tonya, In traditional scalloped potatoes, adding flour between layers basically holds and thickens the sauce in between each layer while it bakes in the oven. This step is really not necessary in this recipe since you are making a cheese sauce to pour over the zucchini. I hope this helps.
Alpa
I do view your site, but it goes on and on… I was looking at the zucchini recipe but gave up as it just kept going on and on.
Like you, patience is not my strong point. Cooking for a family of 6 I don’t have time for reading long recipes, a shame, as it looked good. Sorry.
Thanks anyway.
Wholesome Yum M
Hi Alpa, If you would like to skip the post you can go straight to the recipe by using the ‘Jump to Recipe’ button located under the recipe title on the page. I hope this helps.
Amanda C.
Three stars because it TASTED great, but was way too watery. I drained zucchini and patted dry as directed and cooked longer than 35 minutes. I’m going to try it again because it was yummy,but without the 2 tbsp of almond milk in hopes that the moisture will cut down.
Dina Kassir
Hello Maya, I’m having a hard time finding the measurments for different types of Keto Bread and sometimes the recipes. All the videos and commercials on your Blog site are getting in the way. I’m getting a headache. I got your cookbook Wholesome Yum, can’t find a variety of bread recipes in it.
Dina
Wholesome Yum M
Hi Dina, If you can see the recipe cards, then you may need to turn off your browser’s ‘Reader Mode.’ That should allow you to see the amounts listed in the recipe.
Susan
This was soooo good! I made the six portion size for three of us!! Two of us are most of it leaving a small portion for the third when he comes in from work! It’s definate make again meal. Served with cauliflower and salad. Yum yum!
Lacey
What can I substitute for the brie? I’m not a fan of it.
Wholesome Yum M
Hi Lacey, I suggest using Camembert, it behaves similarly to brie in recipes and delicious!
Cathie Davis
I am NOT a brie lover …. cannot tolerate it in any form. What cheese can I substitute for brie in this recipe?
Wholesome Yum M
Hi Cathie, I suggest using Camembert, it behaves similarly to brie in recipes and delicious!
e
Delicious & easy.
Monet
I do not have a casserole dish (sad, I know)… would I be able to bake this in a regular pan?
Wholesome Yum M
Hi Monet, An oven safe bowl would work too. Anything oven safe with high sides to contain the casserole will work fine.
Leslie Metzger
My husband just loves this dish and he keeps the fridge stocked with the ingredients, BUT I’m not a fan. Although my dish looks like the picture here and has a good taste, I don’t like mushy vegetables.
I’ve made this 7 or 8 times for him (not for me, although I eat it freshly baked – leftovers are all his, as the texture gets worse with reheating). I’ve tried several ideas to cut the mush – let the zucchini drain a little longer, use smaller zucchini (less water), lay them out on a paper towel & pat them dry, omit the milk & increase the cream a little, cut down the baking time – nothing has helped. The best part of this casserole for me is the corners – the browned baked cheese has a
little crunch to offset the very soft zucchini.
Not a winner but I’ll keep baking it for him.
Holly B.
Can this casserole be frozen? Can we freeze any zucchini casserole?
Wholesome Yum M
Hi Holly, Yes, this casserole should freeze well. The zucchini will be more delicate once it’s reheated, but it will still taste as good!
Judy
Hi. Do you think it would be a nice alternative to grate the zuchinni instead of slicing it?
Wholesome Yum
That sounds wonderful, Judy! Let me know how it goes!
Maria Bermudez
Can I substitute with yellow squash, I know that probably means more carbs but I have a lot of squash right now haha, thanks
Maya | Wholesome Yum
Hi Maria, Yes, absolutely! The carb difference is very slight and yellow squash are still definitely low carb.
Jackie Nowak
I made it today Sooooo good!!!!!! Thank you
Bill
We made this last night and it was spectacular! Salting the zucchini was a great suggestion and it worked. Simple, quick and superb!
Buffie
Looks awesome! I’m always looking to add more eggplant to my rotation. Do you think that this will work with eggplant too?
Wholesome Yum
Hi Buffie, I think that could work! Don’t skip the salting and draining step, since that will help keep it from getting too watery.
Jennifer
If I want to prepare this the night before and be able to bake it for Easter lunch the next day, can I just stick it in the fridge?
Maya | Wholesome Yum
Hi Jennifer, You can, but it might get a bit more watery. Another option is to slice the zucchini and make the sauce separately ahead, but assemble the day of.
Trish O’Leary
This was delicious!!! Would definitely make again. Followed recipe exactly and was very flavorful!
Leah
This recipe is so delicious! A great way to get some more veggies into my kids too.
Thanks for creating such amazing recipes, can’t wait to try more!
Cookilicious
Vegetarian casseroles are my go-to when I am in a hurry especially on weeknights! Loved how simple and easy your recipe is.
Amy
This looks so comforting and delicious, I love it!
Sonal
In love with the Zucchini au gratin. Loved your tips as well.
Sandi
What a delicious side dish…it even convinced my kids to try zucchini.
Gloria
You can NEVER have too many zucchini recipes, especially during the growing season. You will never miss the carbs with all the cheese here. This is such a great dish to take along to a potluck. I know my family loves this too.
Shanika
I love eating casseroles but never used zucchini before trying this! This was so good! Definitely, need to make this again!
Kate Cordova
Hi Maya,
What do you think about adding ground beef to make it a main course? Haven’t made it yet, but sounds wonderful.
Kate
Maya | Wholesome Yum
Hi Kate, Sure, you can definitely do that! Just brown it on the stovetop first.
Breann
I’m curious if this dish would work well using heavy cream instead of almond milk? I’ve tried zucchini au gratin twice before (it just turns out an oily mess). Wondering if using heavy cream is the reason? But my husband is allergic to almond. Any ideas?
Maya | Wholesome Yum
Hi Breann, That should work, but you might need a bit more since it’s thicker. I can’t comment on why other recipes might not have turned out, though. I’ve tested this one a couple times and it works at least as written.
Brandon Mercker
Prep time 10 minutes… first step 45 minutes…
Maya | Wholesome Yum
Hi Brandon, The prep time refers to active time prepping. The step to drain the zucchini is not hands-on prep time. Hope you’ll get the chance to try the recipe.
Luciana Varverud
Hi! I baked this recipe ahead of time and then froze it. I forgot to bake it for only half the time and then freeze it. I cooked all the way and then froze it. How should I reheat it? Thanks!
Maya | Wholesome Yum
Hi Luciana, No problem – you can still just reheat it in the oven. It just tastes slightly more fresh the other way, but will still be fine!
Doreen
This was delicious!! I had to use goat cheese as I cannot drink cow’s milk or anything made with it, but I still found the recipe really tasty.
Maya | Wholesome Yum
I am so happy you liked it, Doreen! Thanks for stopping by!
Gerry Clough
Err low carb? with cheese and heavy cream?
Anyway I try to have no meat for 2 days a week and I had all the ingredients except cream for this recipe.
Just used some 2% milk instead and it tasted great!!
Easy peasy and tasty – big thumbs up!
Maya | Wholesome Yum
Hi Gerry, Yes, both cheese and heavy cream are very low carb. 🙂 I’m glad you liked the recipe. Keep in mind that 2% milk does have a fair amount of carbs if that matters to you, but otherwise works just fine.
Dee
We made this creamy cheesy zucchini dish for dinner with steak…it was delicious!!! I used shredded cheese on top
and cream cheese inside!! Only changed it because I didn’t have the other ingredients…
Maya | Wholesome Yum
I am so happy you liked it, Dee! Thanks for stopping by!
Kimberly
I made this casserole and it had way too much liquid, was very crunchy, and was not a casserole per se. It had no cheese around the zucchini. Only on top. I followed the instructions to the letter. What did I do wrong?
Maya | Wholesome Yum
Hi Kimberly, Sorry you had issues with it. It sounds like it definitely needed to be cooked for longer, as the zucchini should not be crunchy. Possible reasons for them being crunchy include slicing the zucchini thicker (it needs to be 1/4-inch thick slices), your oven running a little cool, or simply taking the pan out too soon (the cheese needs to be dark golden brown and zucchini should be soft). Finally, if there was a lot of liquid, the zucchini likely needed to sit over the sink to drain for longer, or you needed to pat dry more to get rid of the moisture. If you sliced yours thicker, that could contribute to this as well. The sauce should be all around the zucchini, but in the original I did only place the cheese on top. I actually love your feedback on that, so I re-tested the recipe today and modified it to include some cheese between the rows as well. Hope it works out better next time!
Sarah
You mention the draining of the zucchini step at the beginning yet you never mention when you actually do it in the recipe. What the heck?
Maya | Wholesome Yum
Hi Sarah, The draining step is right on the recipe card in step 1.
Debbie
I made this for a Memorial Day get together. It was amazing! I had requests for the recipe.
Maya | Wholesome Yum
Thank you so much, Debbie! I’m glad you liked it.
Kamala Ayyagari
Could I make it to freeze? And how would I do it?
Maya | Wholesome Yum
Hi Kamala, You can make the recipe as written and pre-bake for about half the time, then let cool to room temperature and freeze. Later you can bake from frozen until hot and bubbly. The texture may be slightly different than fresh but should still work.
Alison
I made this under protest as I really don’t like courgettes, but I’m staying with my daughter who orders a veg box each week and it’s the only thing I could find that I thought looked ok to use up her courgettes.
Well I must say it was absolutely delisious and went perfectly with our
roast chicken. Lovely recipe
Maya | Wholesome Yum
Yay! I am so happy you liked it, Alison!
Jersey Girl
Amazing recipe. I’m not a fan of zucchini or Italian seasoning, or at least that’s what I thought. Last night I made this recipe for the second time. Delicious. Served it with scallops cooked in butter with a little salt, pepper, smoked paprika and cream in the pan to make a little sauce. Wow! Great recipe if it got me to eat zucchini and like it so much I made it a second time. Thank you, thank you, thank you.
Maya | Wholesome Yum
I’m so glad you liked it! Zucchini can be delicious!
Kaylee
Could cream cheese sub the brie?
Maya | Wholesome Yum
Hi Kaylee, Yes! The flavor would be a little different but still delicious!
Brandy
Hi I am wondering if all your recipes have the nutritional information? I’m excited to start cooking healthy again. The recipes all look delicious
Maya | Wholesome Yum
Hi Brandy, Yes, they do! Thank you!