Roasted Vegetable Frittata

Preheat oven to 400°F. Saute onion in oil in a small ovenproof pan over medium-high heat. Add zucchini and pepper and place pan in oven to roast until vegetables are tender, about 10 minutes. Beat eggs and cheese together in a small bowl. Remove pan from oven and stir egg mixture into vegetables. Season to taste with salt and pepper. Return pan to oven until frittata is cooked through, about 10 to 15 minutes.