An easy zucchini au gratin recipe that’s keto friendly and takes just minutes to prepare. It’s a healthier alternative to the high carb potato recipes.
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A traditional au gratin dish is topped with breadcrumbs, along with cheese. Then it’s cooked until perfectly golden brown. But using zucchini and skipping the crispy topping makes it a fantastic low carb side dish.
Now, when most people think of au gratin, the dish that comes to mind is potatoes. But potatoes, in my opinion, are at the top of the list for being one of vegetables to avoid. That’s because the starch from potatoes can rapidly metabolize into sugar.
But I’m here to tell you that it’s not necessary to make a traditional-tasting au gratin dish with potatoes. Just sub it out for a healthier veggie like I do in this keto zucchini au gratin.
When replacing potatoes with a low-starch veggie, it sometimes help to partially cook the veggie first. And then, you can bake the low-starch veggie in the au gratin pan.
But before getting into the recipe, I want to tell you why I love cooking with this specific veggie.
Is Zucchini Keto Friendly?
You bet! Zucchini is one of the best low carb vegetables. One medium-sized zucchini has about 6 grams of carb of which 2 grams are fiber. And since you would never eat a whole one, a serving should only add one or two grams net
If you’re following a ketogenic lifestyle, it’s definitely one of the best low-carb veggies for a keto diet. So without further ado, let’s get cooking….
How to make a keto zucchini au gratin
If you want to feed your hungry family or a dinner party of 8, here’s what you’ll need:
- 2 tablespoons of butter or ghee (clarified butter)
- a couple cloves of garlic
- either a tablespoon of onion flakes or 3 tablespoons of chopped fresh raw onion
- a half-cup of almond milk if you want a lighter dairy footprint (or make it richer by adding heavy cream)
- 2 cups of shredded cheddar cheese (non-dairy cheddar cheese can work too)
- And last but not least, 2 medium zucchinis sliced.
To make it, the first thing you need to do is in an oven-proof skillet, over medium heat, melt the butter. Then, add the garlic and onion and cook until fragrant, about 2 to 3 minutes.
At this point, you’ll want to add the almond milk (or cream). Place on simmer and continue to let it cook until it starts to boil. But don’t turn the stove top off just yet.
At this point, you’ll want to delicately and slowly add half the shredded cheese. Then stir until it melts.
Next, stir in the veggie. All the slices should be soaked and covered in the sauce. Stir frequently and cook on simmer setting for another 5 minutes.
Now it’s time to add the rest of the cheese. And the final step in preparing this zucchini gratin is baking it in the oven at 400 for about 20 minutes until the top is browned.
Oh yeah, and one more thing: enjoy!
Final cooking tips
I tested out a dairy-free cheese in the recipe. But it didn’t melt well in the oven. I’d be curious if any of you have solutions to that.
The great thing about this zucchini au gratin dish is it’s gluten-free as there’s no bread crumbs. But I suppose seasoned crushed pork rinds could be used make it more of an authentic style dish and still keep it keto. You can also used crumbs from toasted keto bread.
Other Low Carb Zucchini Recipes
I use the veggie many of my recipes. Turkey Zucchini meatballs? Check. Zucchini nachos? Nailed it.
I’ve also transformed the nutrient-dense, low-calorie veggie into a healthier french fry, pizza slices, and cheese wedges. And I’ve of course created several recipes with it using zoodles like my zucchini noodle casserole.
Looking for another recipe to use up your zucchini? Check out my zucchini chicken casserole.
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📖 Recipe
Zucchini Gratin
Video
Ingredients
- 2 tablespoons butter or ghee
- 2 cloves garlic minced
- 1 tablespoon onion flakes or 3 tablespoons chopped fresh
- ½ cup almond milk or heavy cream for richer sauce
- 2 cups cheddar cheese shredded
- 2 medium zucchini sliced
Instructions
- In oven proof skillet over medium heat, melt the butter. Then add the garlic and onion and cook until browned and fragrant.
- Add the almond milk (or cream) and simmer until it starts to boil. Slowly add in 1 cup of the shredded cheese and stir until melted.
- Stir in the sliced zucchini until all are covered with the sauce. Stir and cook for another 5 minutes.
- Sprinkle remaining 1 cup of cheddar cheese on top. Then bake in 400°F oven until top is browned (about 20 minutes).
Notes
Low Carb Sweeteners | Keto Sweetener Conversion Chart
Nutrition
Additional Info
Note on Nutritional Information
Nutritional information for the recipe is provided as a courtesy and is approximate only. We cannot guarantee the accuracy of the nutritional information given for any recipe on this site. Erythritol carbs are not included in carb counts as it has been shown not to impact blood sugar. Net carbs are the total carbs minus fiber.
Unauthorized use of this material without written permission from Lisa MarcAurele is strictly prohibited unless for personal offline purposes.
Single photos may be used, provided that full credit is given to LowCarbYum.com along with a link back to the original content.
Teresa Michelle Sajevic
Ohhhh my goodness! This is amazing!!! I quadrupled it because we have a big family of big eaters. Everyone loved it!!!
I had be given so many zucchini I didn’t know what to do… well. I googled low carb zucchini and I got this. While scanning I saw a post for mock apple crumble. Hello???? Thank you!! I used half my zucchini up for dinner and dessert without breaking my bank, back or diet!! Thanks a million!
Linda
Lisa love your recipes. Would it be ok to share them with a small private group of my friends on our private group share recipes site?
Linda
Lisa MarcAurele
You can email me at [email protected] to discuss.
Joyce Wade
Lisa, I use a lot of your receipes and I have your book. I don't understand why those of you that write receipes say things like to medium zucchini etc..What does a sm., med., or large look like to you? We all see things differently. I wish you would all use measurements that are universal like so many cups, spoons etc. That I can know how to find. Don't intend this to be grumpy and you are not the only one who does this. It is just one of my pet peeves. Just think about it and Have a great day!
Lisa MarcAurele
Sorry about that! Medium zucchini yields about 2 cups. Small zucchini about 1.5 cups. I rarely use a large zucchini in recipes.
Lisa
I love this recipe. Ive made it about 10 times already. I always use garlic powder and onion powder because that's all I had at first so I always use that. I use butter and heavy cream. I usually make it as a side dish with roast pork tenderloin. It's just my favorite! Thanks!
carol paez
Okay. So I am guessing the garlic cloves are to be chopped, minced, or crushed?
Lisa MarcAurele
Minced. I'll go in and add that.
Linda
Oh yum! Can't believe it's a keto-friendly. This is definitely a recipe that will be on repeat weekly.
paleoglutenfreeguy
Love it when you can make dishes (especially veggie dishes) both healthful and indulgent. This looks like total comfort food!
Zuzana
A perfect addition to our list. So many Zucchinis growing in the garden.
Jean Choi
I've been swimming in zucchini these days so this is such a perfect recipe! What a great idea.
Hope
Loving this low carb version of gratin. This is going on my menu for the weekend!
Erin
I always eat the entire batch of potatoes au gratin and then just want to sleep the rest of the day! This is the right recipe for me. 🙂
Annemarie
This looks delicious! My kids don't normally enjoy zucchini, but the cheese might be just the thing to encourage them. 🙂
ChihYu
Zucchini and delicious, melty cheese! I'm in! And the prep is simple!
Megan Stevens
I LOVE the heavy cream version! 😉 My favorite veggie too! Thanks for this great recipe!
Raia Todd
I absolutely love this. It's such a great way to get my kids to eat zucchini! Haha.
Cynthia | What A Girl Eats
I seem to always buy zucchini every week. It's so versatile! I can't wait to make this!
Joni Gomes
I'm a sucker for a cheesy gratin! Love this healthy spin on it with the zucchini! Very summer appropriate!
Thom Davis
I think this would be a good substitute for a high carb side dish for Thanksgiving. Since zucchini aren't seasonal right now, do you think frozen would work? I could also see this working with yellow squash (fresh or frozen) maybe.
Lisa MarcAurele
Yellow squash works great too. I'm not sure about frozen zucchini as it can be a lot softer than fresh. But you can certainly give it it a try.
monika
Your wrote: (I haven’t personally used Daiya, the popular brand of vegan cheese substitute. If you do decide to use it please leave a comment on this post and let me know how it turns out and if you have to adjust the serving size.) BUT later in the post you wrote that your family used dairy-free cheese...
So which is it and which cheese did YOU use?
Lisa MarcAurele
I have used Daiya, but I like the So Delicious brand better. The first comment is an error.
Annette Gamble
I read that you were trying to avoid dairy because of inflammation. Have you tried goat milk and goat cheese. My daughter was allergic to cow dairy but not goat milk, butter and cheese. It melts just like cow cheese.
Lisa
Yes. Goat milk doesn't have the same reaction and I'm pretty sure it's because it's an A2 casein in goat's milk whereas most cow milk is A1.