This low carb cheesy zucchini gratin is a healthier alternative to potato gratin. It’s a tasty low carb and gluten-free side dish the family will enjoy.
A simple keto zucchini dish that is easy to make and makes a great dinner dish with minimum fuss. You can bake this ahead then re-heat when you are ready to eat. I find it hearty enough to eat by itself with a green side salad.

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What is in this Zucchini Gratin?
I used a mixture of green and yellow squash zucchini for a colorful dish. I find the yellow zucchini adds a touch of sweetness to It. If you wanted a sweet side dish only use the yellow zucchini.
For the creamy cheese sauce, I used mascarpone instead of heavy cream for a thicker sauce. You could use cream cheese for an extra creamy dish.
I kept the seasoning very basic but adding herbs such as thyme or a dash of nutmeg would be a great addition to this dish. Whatever you used to use in your potato gratin, throw it in this gratin too!
Ingredients

- Zucchini - we used a mixture of yellow and green zucchini as the yellow zucchini gives an additional sweetness to the dish. This is a great use of summer squash.
- Mascarpone cheese - cream cheese could be substituted.
- Parmesan cheese - freshly grated and nothing from a tub.
- Cheddar cheese - we use a strong British Cheddar cheese.
- Olive oil - for a richer dish, butter could be used to cook the vegetables.

How to make Zucchini Gratin
A simple low carb zucchini recipe that makes a great side dish anytime of the year.

Saute onion and garlic.

Add thinly sliced zucchini and cook until golden on both sides.

Mix mascarpone and egg.

Add the rest of the cheeses.

Place cooked vegetables in a casserole dish.

Top with cheese mixture and bake.
Recipe Tips
Ensure that the zucchini slices are thin and even for this zucchini au gratin dish. Mine were sliced about a quarter of an inch and held their shape well without becoming too limp and watery.
Try to use fresh Parmesan cheese if you can get it for a strong taste. You could use other cheese such as Gruyere, Fontina or Monterey Jack for other flavours.
This dish could be turned into a cheesy zucchini bake if you spiralise the zucchini instead of slicing it.

What cheese goes with zucchini?
Several types of cheese pair well with zucchini, and the choice depends on personal preferences and the specific dish you're making. Here are some popular cheese options that complement zucchini nicely:
- Parmesan: Parmesan cheese adds a salty, nutty flavor to zucchini dishes, making it a classic and delicious choice. Grated or shaved Parmesan works well on roasted zucchini, in pasta dishes, or on top of zucchini gratins.
- Feta: Feta cheese's tangy and salty taste pairs nicely with zucchini, especially in Mediterranean-style recipes. Try it in salads, stuffed zucchini, or mixed with roasted zucchini and cherry tomatoes.
- Goat Cheese: Goat cheese's creamy and slightly tangy flavor contrasts well with the mild taste of zucchini. Use it in stuffed zucchini, on zucchini pizzas, or in creamy pasta dishes.
- Gouda: Smoked Gouda, in particular, complements zucchini with its rich and slightly sweet taste. It's excellent in casseroles, quiches, or melted on top of grilled zucchini.
- Mozzarella: Mozzarella cheese adds a gooey, melty texture to zucchini dishes. It's a fantastic choice for zucchini lasagna, stuffed zucchini boats, or simple zucchini and tomato bakes.
- Ricotta: Ricotta cheese's creamy and mild flavor works well in zucchini-based dishes like lasagna, stuffed shells, or savory zucchini tarts.
- Cheddar: Sharp cheddar cheese can add a robust flavor to zucchini dishes. Use it in zucchini and cheddar muffins, cheesy zucchini gratin, or zucchini and cheddar fritters.
- Blue Cheese: For those who enjoy strong flavors, blue cheese can be an interesting addition to zucchini recipes. It pairs well in salads, stuffed zucchini, or as a topping for grilled zucchini.
Storage
Any leftovers should be stored in the fridge, in an air tight container. Reheat in the oven or microwave. This gratin should last up to 3 to 4 days in the fridge.
Watch how to make it
OTHER LOW CARB SIDE DISHES TO TRY:
Cauliflower Cheese & Onion Croquettes
Brussel Sprout & Cauliflower Gratin
Cauliflower Cheese with Walnuts & Stilton

Zucchini Gratin
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Ingredients
- 3 zucchini sliced into rounds
- 1 onion chopped
- 2 cloves garlic chopped
- ½ cup Parmesan cheese grated
- 8 oz Mascarpone cheese
- 1 large egg
- 2 oz Cheddar cheese
- 2 oz Mozzarella cheese
- 3 tablespoons olive oil
- 1 teaspoon salt
- 1 teaspoon black pepper
Instructions
- Preheat the oven to 200C/400F degrees.
- Heat the olive oil in a large frying pan on a medium heat. Add the onion and garlic and cook for 5 minutes.
- Add the zucchini and cook until lightly golden on both sides.
- Season the vegetables with the salt and pepper.
- In a bowl, beat the mascarpone with the egg until smooth.
- Add the parmesan & Cheddar cheese and stir well.
- Layer the vegetables in a baking dish.
- Pour the cheese mixture over the zucchini and sprinkle the Mozzarella on top.
- Bake for 30 minutes.
Notes
Nutrition
The information shown is an estimate provided by an online nutrition calculator.





