Preheat broiler. In a 10-in. cast-iron or ovenproof skillet, saute onion, peppers and garlic in 2 tablespoons of oil until the vegetables are tender. Remove vegetables with a slotted spoon; set aside.
In the same skillet over medium heat, lightly brown potatoes in remaining oil. Add vegetable mixture and zucchini; cook for 4 minutes.
In a bowl, beat eggs, salt and pepper; pour over vegetables. Cover and cook for 8-10 minutes or until eggs are nearly set. Broil 6 in. from the heat for 2 minutes or until eggs are set on top. Cut into wedges.