This low carb cheesy zucchini gratin is a healthier alternative to potato gratin. It’s a tasty side dish the family will enjoy.
A simple low carb 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.

What is in this Zucchini Gratin?
I used a mixture of green and yellow zucchini for a colourful 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!

How to make Zucchini Gratin
Ensure that the zucchini slices are thin and even. 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.

OTHER SIDE DISHES TO TRY:
Cauliflower Cheese & Onion Croquettes
Brussel Sprout & Cauliflower Gratin
Cauliflower Cheese with Walnuts & Stilton

Zucchini Gratin
Ingredients
- 3 zucchini sliced into rounds
- 1 onion chopped
- 2 cloves garlic chopped
- ½ cup Parmesan cheese grated
- 8 oz Mascarpone cheese
- 1 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
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Zandra
Is this something you can make ahead of time and if so how long can you keep it in the frig before cooking?
Angela Coleby
You could make this ahead of time and it should be okay in the fridge for about 4 hours before cooking.
Danielle
Love this dish! So yummy and lots of compliments. Has anyone tried making a day or two ahead of time?
Kristen
THIS IS DELICIOUS!!! I usually use cream and the mascarpone/egg/cheese mixture was a delicious, decadent change. I used a cheddar/gouda cheese blend instead of just cheddar, and omitted the mozzarella. I will definitely be making again!
Angela Coleby
Delighted you enjoyed it! I love the cheese blend you used too!
Ariana
If you use heavy cream or cream cheese to make it cheesier what do you omit? Also how much of this do you use if you were to add the heavy cream or cream cheese? Do you add it with the regular recipe?
Angela Coleby
I would omit the mascarpone but keep the measurements the same for the swap.
Dana Lynch
So yummy! My family that doesn’t usually like vegetables even liked.
Maxine Horn
Adapted this, left out the onion but replaced with two leaks cut to same width as courgette / zucchini and replaced cheddar with Gouda, added two teaspoons of English mustard. Worked brilliantly as enhanced the tanginess of the sauce.
Angela Coleby
Sounds delicious!
Susan
Where do you put the cheddar cheese?
Angela Coleby
In the cheese sauce with the Parmesan.
Kylie Squire
What do i do with the onion and garlic?
Angela Coleby
They are cooked first before the zucchini.