This cheesy keto zucchini gratin is an easy, creamy low carb side dish that’s perfect for using up fresh summer zucchini. If you’re looking for a simple keto zucchini recipe that actually gets eaten (even by picky eaters), this is the one!

You can skip the origin story for this easy keto zucchini gratin but using the jump to recipe button at the top of the post.
When Mr. Hungry decided to join me on keto recently to drop a few pounds after our carb heavy trip to the states in October, I had mixed feelings about it. He said he was doing it to lose weight and support me in my keto efforts, but as you wives know – that usually means more work for us.
“What can I eat?”
“I’m starving, do we have any snacks?”
“Did you eat all the bacon again?” (Yes, yes I did.)
Don’t get me wrong, Mr. Hungry does more than his fair share around the house, but cooking is mostly my department. And that would be fine – except he hates 90% or more of the things I love to eat on keto.
So while I would be perfectly happy throwing some Better than Potatoes Cheesy Cauliflower Puree in a bowl for myself and calling it dinner (which I do a lot) – he won’t touch anything that has cauliflower in it with a 10 foot pole.
Or broccoli, or spinach, or pretty much any vegetable that isn’t potatoes. Which makes it really hard to make keto friendly meals that he’ll actually eat.

Cue this keto zucchini gratin…
Zucchini is on the list of less offensive but not his favorite (i.e. “I don’t love it, but it doesn’t make me want to kill myself”) vegetables that I sometimes sneak in there.
Those of you with picky eaters in the family know the struggle. Whether it’s finicky kids or veggie phobic spouses, making something that everybody will eat and like is a challenge sometimes.
I find that to be true of keto side dishes most of all. Who doesn’t love a good steak or roasted chicken? But coming up with tasty low carb veggie side dishes that go with those main courses night after night can be a problem.

So when this Easy Keto Zucchini Gratin went down and everybody liked it – I mentally high-fived myself and made it a regular thing. You’re going to want to do the same when you try it!
I used pepper jack cheese the first few times I made this zucchini gratin, and we love the mild heat that it adds – but if you prefer cheddar I tried that too and it’s also delicious.
In fact, I’m pretty sure you can’t go wrong with almost any cheese in this keto zucchini gratin – so you do you, it’s all good.

Any time a keto dinner (complete with vegetables) goes on the table and nobody is whining or complaining?
That’s a win my friends – and I’ll take it!
Let me know in the comments if this zucchini gratin passed the test with your family!
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Easy Keto Zucchini Gratin – Low Carb
- Total Time: 56 minutes
- Yield: 9 servings 1x
- Diet: Diabetic
Description
This Easy Zucchini Gratin has become a staple in our house! It’s cheesy and creamy, super easy to throw together, and the perfect low carb side dish for your keto diet!
Ingredients
- 4 cups sliced raw zucchini
- 1 small onion, peeled and sliced thin
- salt and pepper to taste
- 1 1/2 cups shredded pepper jack cheese
- 2 tablespoons butter
- 1/2 teaspoon garlic powder
- 1/2 cup heavy whipping cream
- 1/4 teaspoon xanthan gum
Instructions
- Preheat oven to 375 degrees (F).
- Grease a 9×9 or equivalent oven proof pan.
- Overlap 1/3 of the zucchini and onion slices in the pan, then season with salt and pepper and sprinkle with 1/2 cup of shredded cheese.
- Repeat two more times until you have three layers and have used up all of the zucchini, onions, and shredded cheese.
- Combine the garlic powder, butter, heavy cream, and xanthan gum in a microwave safe dish.
- Heat for one minute or until the butter has melted. Whisk until smooth.
- Gently pour the butter and cream mixture over the zucchini layers.
- Bake at 375 degrees (F) for about 45 minutes, or until the liquid has thickened and the top is golden brown.
- Serve warm.
Notes
Depending on your zucchini, you may find it takes longer to cook in order to get your sauce to reduce. If you find it very watery after the 45 minutes, lower the oven temp to 350 and cook it another 10 minutes or so.
- Prep Time: 10 minutes
- Cook Time: 46 minutes
- Category: keto side dishes
- Method: oven
- Cuisine: American
Nutrition
- Serving Size: 3 x 3 square
- Calories: 230
- Fat: 20g
- Carbohydrates: 3g net
- Protein: 8g
More Zucchini Recipes You Will Love
If you’re overrun with extra zucchini, here are a few more low carb favorites:
Keto Chocolate Zucchini Cupcakes w/ Mocha Frosting
Easy Four Cheese Pesto Zoodles
keto crispy baked zucchini slices – an edible mosaic
To get more fantastic keto recipes, download my super bundle of FIVE e-books for just $19.99!

TERRY MOON says
Can I make this dish in the morning and then bake it after work?
Mellissa Sevigny says
I’m not sure that will give you the best results – the zucchini might oxidize and/or release a bunch of liquid into the dish. I would prep all of the ingredients and then assemble it (should be quick if everything is prepped) and bake the casserole right before eating.
Cari says
I’m going to show this to my husband (he’s the cook) and try it! I just wanted to comment that I feel the same way about cauliflower as Mr. Hungry, and I really like the keto loaded “faked potato,” using cauliflower, cheddar and cream cheeses, bacon, and green onions. It does NOT taste like cauliflower at all.
Mellissa Sevigny says
Thanks for the suggestion Cari, I’ll see if I can get that one by him! 😂
Linda says
I made this tonight and I had to comment that it was absolutely delicious and so easy to make. I’ll definitely make this again. Thanks for sharing.
Mellissa Sevigny says
So happy you liked it, thanks for taking the time to let me know!
Terry Stenson says
This is my very favorite zucchini recipe ever! I have made this several tines, and it’s always come out great! I’ve tried other recipes, some that are similar but yours is the clear winner. The pepper jack cheese is the best choice, Thank-you for this and many other recipes I’ve book marked.
Mellissa Sevigny says
Thanks so much Terry, I love hearing that this one is still a favorite!
Tammy Predolich says
How thick are you slicing the zucchini and onions?
Mellissa Sevigny says
Slice about 1/4 inch thick.