4 tablespoons of chopped onion
3 tablespoons of melted butter
1 cup of milk
2 tablespoons of flour
Salt and pepper
2 eggs separated
3 cups of leftover mashed potatoes

Brown the onion in butter, add flour and then milk. Add the yolks and sauce to potatoes and mix well. The fold in beaten egg whites. Bake in  a greased oven dish about 25 - 30 minutes at 350ºF.