Preparation Cook potato in saucepan of boiling salted water until tender, about 8 minutes. Drain. Heat oil in large ovenproof skillet over medium-high heat. Add pepper and onion; sauté until tender, about 6 minutes. Add potato, garlic, and oregano; sauté 1 minute. Whisk eggs, salt, and pepper in medium bowl. Pour over vegetables in skillet. Reduce heat to medium-low, cover skillet, and cook until eggs are set around edges, about 8 minutes. Sprinkle with cheese. Meanwhile, preheat broiler. Place skillet in broiler 4 to 5 inches from heat source and cook until cheese is melted and just browned, about 2 minutes. Let frittata stand 1 minute. Cut into 8 wedges.
Preparation Cook potato in saucepan of boiling salted water until tender, about 8 minutes. Drain. Heat oil in large ovenproof skillet over medium-high heat. Add pepper and onion; sauté until tender, about 6 minutes. Add potato, garlic, and oregano; sauté 1 minute. Whisk eggs, salt, and pepper in medium bowl. Pour over vegetables in skillet. Reduce heat to medium-low, cover skillet, and cook until eggs are set around edges, about 8 minutes. Sprinkle with cheese. Meanwhile, preheat broiler. Place skillet in broiler 4 to 5 inches from heat source and cook until cheese is melted and just browned, about 2 minutes. Let frittata stand 1 minute. Cut into 8 wedges.