Step 1

Preheat the oven to 400 °F. Lightly spray a deep-dish 9-inch pie plate with nonstick cooking spray; set aside.

Step 2

In the prepared pie plate, evenly layer zucchini (1 cup),

Step 3

then tomato (1 cup),

Step 4

then onion (1/2 cup),

Step 5

then cheese (1/3 cup Parmesan cheese + 1/2 cup Mozzarella cheese).

Step 6

In a large mixing bowl, whisk together the remaining ingredients with a fork until blended.

Step 7

Pour mixture into pie plate over vegetables.

Step 8

Bake in the preheated oven, until the knife inserted in the center, comes out clean, about 35 minutes. Cool at least 10 minutes before serving.