Lighter Zucchini Gratin – A Healthy Side Dish

This lighter zucchini gratin features sliced zucchini layered along with cheese and a creamy white sauce. Topped with cheese and breadcrumbs.

It’s a healthy and simple side dish to help you tackle your zucchini glut.

Lighter Zucchini Gratin

Let’s be honest, zucchini on their own don’t have much flavour. And if you leave them too long and they become marrows, there’s even less. They’re predominantly water when they get too big.

They are, however, great vessels for other flavours. In this dish, I’ve added plenty of fresh thyme and garlic.

As for the cheese, that’s a way to add in more flavour too. If you like it mild, an Edam works well, or maybe you like something with a little more bite such as a gruyere, or a parmesan. Or use half of each! You choose.

Water in zucchinis

It’s best with zucchini as there is a little less water but I have also made this with the big marrows I have accidentally missed in the garden. There’s a key step that can’t be missed especially if marrows are on the menu; they need to be salted and left for a while to draw out the excess moisture. Otherwise, the end dish will be too watery (delicious, but a little too sloppy.)

It’s easy though. They’re sliced, sprinkled with salt and then left in a colander for 30-45 minutes (longer for marrows). Afterwards, pat them dry thoroughly with a clean towel or paper towels.

The sauce

The white sauce is olive oil, garlic, flour, fresh thyme, milk, salt and pepper. This recipe has no heavy creams, making it a nice and healthy side dish.

I layer the sliced zucchini in a casserole dish, with a little grated cheese. Then the white sauce is poured over the top, along with more cheese and plenty of breadcrumbs.

The dish is baked for around 30-35 minutes until bubbling and golden brown.

Leave it to stand for 10 minutes before slicing because it will be so HOT! There’s a chance there will still be some excess liquid in the dish, even with salting. Using a slotted spoon to scoop it out will leave the liquid behind.

Lighter Zucchini Gratin
Lighter Zucchini Gratin

Lighter Zucchini Gratin

Yield: 6 people
Prep Time: 20 minutes
Cook Time: 35 minutes
Salting time: 45 minutes
Total Time: 1 hour 40 minutes

Sliced zucchini are layered along with cheese and a creamy white sauce, then topped with cheese and breadcrumbs.


  • 800-900g zucchini, sliced into rounds, 3mm thick
  • 2 tsp salt
  • 2 Tbsp olive oil
  • 3 cloves fresh garlic, crushed
  • 3 Tbsp all-purpose flour
  • 1 Tbsp fresh thyme (or 1/2 tsp dried)
  • 2 cups milk
  • 1/8 tsp ground nutmeg
  • Pepper, to taste
  • 1 cup grated cheese
  • 1/4 cup breadcrumbs


  1. Sprinkle the zucchini slices with 1 1/2 tsp of salt and toss to coat.
  2. Place the zucchini slices in a colander and leave them to sit and drain for 30-45 minutes.
  3. Pat the slices dry thoroughly with a clean tea towel or paper towels.
  4. Preheat the oven to 200 °C .
  5. Place a deep saucepan over medium heat and add the oil.
  6. Once warm, add the garlic and fresh thyme and allow them to sweat for 2 minutes.
  7. Add in the flour and whisk it together. Fry the flour in the oil for 1-2 minutes.
  8. Pour in the milk 1/4 cup at a time. Keep whisking and let the sauce come to a simmer and thicken in between each addition.
  9. Add the nutmeg and 1/2 tsp of salt. Whisk it together until it starts to bubble and thicken.
  10. Once thickened, take it off the heat and add more salt and pepper to taste.
  11. Layer the zucchini in a large casserole dish. Halfway through layering, sprinkle over 1/2 cup grated cheese, then top with the remaining zucchini.
  12. Pour over the white sauce, then top with grated cheese and breadcrumbs.
  13. Bake for 30-35 minutes until golden brown and bubbling.
  14. Remove from the oven and let it stand for 10 minutes to cool before serving.
Nutrition Information:
Yield: 6 Serving Size: 1 grams
Amount Per Serving: Calories: 212Total Fat: 13.2gSaturated Fat: 5.8gUnsaturated Fat: 0gSodium: 42mgCarbohydrates: 15.5gFiber: 2.1gSugar: 6.4gProtein: 10.1g

Sharing is caring!

Similar Posts

Leave a Reply

Your email address will not be published. Required fields are marked *