Preheat oven to 400 degrees. Brush a 9 1/2-inch deep-dish pie plate with 1 teaspoon olive oil. Drain any liquid from leftover roasted zucchini, onion, and peppers; place in pie plate.
In a large bowl, beat eggs with grated Parmesan
cheese, coarse salt, and ground pepper; pour over vegetables.
Bake until top is golden and center is set, 35 to 40 minutes; cool 5 minutes before serving.