Party Potatoes
["1 pt. milk", "2/3 lb. Velveeta cheese", "8 oz. grated sharp Cheddar cheese", "3 sticks margarine", "4 (48 oz.) pkg. hash browns", "onions (optional)"]
["One hour before serving, heat the milk, cheeses and margarine together until all are melted.", "Pour over thawed potatoes.", "Bake for 1 hour at 350\u00b0."]
["milk", "Velveeta cheese", "grated sharp", "margarine", "hash browns", "onions"]