Zucchini and Onion Gratin

Zucchini and Onion GratinRecipe
Photo: Jennifer Causey; Styling: Ginny Branch
You can serve this side dish hot, but it's also great at room temperature.


Serves 6 (serving size: about 1 cup)
Total time: 45 Minutes

Recipe from

Cooking Light

Recipe Time

Hands-on: 21 Minutes
Total: 45 Minutes

Nutritional Information

Calories 92
Fat 6.3 g
Satfat 1.6 g
Monofat 3.7 g
Polyfat 0.6 g
Protein 4 g
Carbohydrate 7 g
Fiber 2 g
Cholesterol 4 mg
Iron 1 mg
Sodium 224 mg
Calcium 79 mg


2 tablespoons olive oil, divided
1 large onion, quartered lengthwise and thinly sliced
1 tablespoon tomato paste
2 teaspoons grated lemon rind
1 teaspoon fresh thyme leaves
3/8 teaspoon kosher salt, divided
1/4 teaspoon freshly ground black pepper
1 1/2 pounds zucchini, diagonally sliced into 1/4-inch-thick pieces
1 ounce Parmesan cheese, grated (about 1/4 cup)


1. Heat a large skillet over medium heat. Add 1 tablespoon oil to pan; swirl to coat. Add onion; cook 6 minutes, stirring occasionally. Stir in tomato paste; cook 2 minutes. Stir in rind, thyme, 1/8 teaspoon salt, and pepper; cook 2 minutes, stirring occasionally.

2. Preheat broiler to high.

3. Arrange zucchini on a jelly-roll pan. Drizzle with remaining 1 tablespoon oil; toss. Broil 7 minutes or until lightly charred. Sprinkle with remaining 1/4 teaspoon salt.

4. Preheat oven to 375°.

5. Spread onion mixture in a 2-quart gratin dish. Arrange zucchini mixture over onion mixture. Sprinkle with cheese. Cover and bake at 375° for 25 minutes. Remove from oven.

6. Preheat broiler to high.

7. Uncover zucchini mixture; broil 1 1/2 minutes or until lightly browned.