1Heat oven to 325ºF. Mix bell pepper, onion, potatoes, 2 tablespoons cheese, the salt and pepper in large bowl.
2Pour butter and oil into rectangular pan, 13x9x2 inches. Tilt pan to coat the bottom. Spread potato mixture in pan.
3Bake uncovered about 35 minutes. Run a spatula under edge of potato mixture; turn potato mixture over to other side. Bake uncovered about 5 minutes longer or until golden brown. Sprinkle with additional cheese before serving.