Step 1

Preheat oven to 400F. Over medium-low heat, heat oil in a 10-inch skillet. Stir in onion and cook until slightly brown, about 10 minutes. Add peppers and cook 5 more minutes, then add zucchini. Season with salt and pepper and cook 3 more minutes stirring occasionally.

Step 2

In a medium bowl whisk eggs, Parmesan, salt and pepper.

Step 3

Add eggs to the skillet making sure eggs cover all the vegetables. When the edges begin to set (about 2 minutes) move skillet to oven.

Step 4

Cook about 10-15 minutes, or until frittata is completely cooked.

Step 5

Serve warm, cut into 4 pieces.