Zucchini Au Gratin

Transform your zucchini into a show-stopping side dish with this creamy and indulgent Zucchini Au Gratin. Tender layers of thinly sliced zucchini are blanketed in a luscious Gruyère cheese sauce, infused with the warmth of garlic and a hint of nutmeg for an irresistible flavor profile. Topped with a golden breadcrumb and Parmesan crust, this baked masterpiece balances rich creaminess with a crispy crunch in every bite. Perfect for dinner parties or a comforting weeknight meal, this recipe is a unique twist on traditional gratins and pairs beautifully with roasted meats or fresh salads. Easy to prepare in under an hour, it’s elegant, satisfying, and sure to be a family favorite.

Nutriscore Rating: 52/100

Prep Time:15 mins

Cook Time:40 mins

Total Time:55 mins

Servings: 6

Ingredients

• 4 medium zucchini
• 3 tablespoons unsalted butter
• 1 small, diced yellow onion
• 2 minced garlic cloves
• 3 tablespoons all-purpose flour
• 1.5 cups whole milk
• 0.5 cups heavy cream
• 1.25 cups grated Gruyère cheese
• 0.5 cups grated Parmesan cheese
• 0.5 cups breadcrumbs
• 1 tablespoon olive oil
• 1 teaspoon salt
• 0.5 teaspoon ground black pepper
• 0.25 teaspoon ground nutmeg
• 2 tablespoons, chopped (optional) fresh parsley

Directions

Step 1

Preheat your oven to 375°F (190°C). Grease an 8x8-inch baking dish with butter or nonstick spray.

Step 2

Using a mandoline or a sharp knife, slice the zucchini into thin, even rounds (about 1/8 inch thick). Set them aside.

Step 3

In a medium saucepan over medium heat, melt 3 tablespoons of butter. Add the diced onion and cook until softened, about 3–4 minutes. Stir in the minced garlic and cook for another 30 seconds until fragrant.

Step 4

Sprinkle the flour over the onion mixture and stir continuously for 1–2 minutes to cook out the raw flour taste.

Step 5

Gradually whisk in the milk and heavy cream, ensuring there are no lumps. Cook the mixture, stirring constantly, until it thickens, about 3–5 minutes.

Step 6

Remove the saucepan from heat and stir in 1 cup of Gruyère cheese, 1/4 cup of Parmesan cheese, salt, black pepper, and nutmeg. Mix until the cheese is melted and smooth.

Step 7

Layer half of the zucchini slices in the prepared baking dish, slightly overlapping each other. Pour half of the cheese sauce evenly over the top. Repeat with the remaining zucchini and cheese sauce.

Step 8

In a small bowl, combine the breadcrumbs, remaining Gruyère and Parmesan cheeses, and olive oil. Sprinkle the breadcrumb mixture evenly over the zucchini and cheese layers.

Step 9

Bake in the preheated oven for 25–30 minutes until the top is golden brown and the zucchini is tender when pierced with a fork.

Step 10

Remove the dish from the oven and let it rest for 5 minutes before serving. Garnish with fresh parsley, if desired.

Nutrition Facts

Serving size	1682.5 grams (1682.5g)

Amount per serving	% Daily Value*
Calories	2424

Total Fat 164.30g	211%
Saturated Fat 93.20g	466%
Polyunsaturated Fat 2.30g
Cholesterol 447mg	149%
Sodium 12536mg	545%
Total Carbohydrate 144.40g	53%
Dietary Fiber 10.80g	39%
Total Sugars 79.40g
Protein 87.50g	175%

Vitamin D 191IU	955%
Calcium 2338mg	180%
Iron 8mg	42%
Potassium 2589mg	55%

*The % Daily Value tells you how much a nutrient in a serving of food contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.

Source of Calories

Fat: 61.5%

Protein: 14.5%

Carbs: 24.0%