Preheat oven to 375.
In a medium sauté pan over medium high heat, add butter and sauté onion until lightly browned, about 6 minutes. Add prosciutto and red pepper and lightly brown, about 4 minutes.
Scatter hash browns and sautéed vegetables over bottom of pie.
In a bowl, add eggs and yolks, milk, cream, salt, pepper and nutmeg and mix well and pour over vegetables. Scatter cheese over top of quiche and place on bottom rack in oven. Bake for 30-35 minutes or until lightly browned and puffed. Remove and allow to set for 5 minutes before serving.
Can be served hot or room temperature.