Ham Casserole

2 cups diced ham
2 cups cubed cheddar cheese
1/2 cup chopped onion
4 cups of boiled and cubed potatoes
white sauce made from butter, flour and milk

Place ham and cheese in the bottom of a casserole dish. Sprinkle with onion. Pour the boiled and cubed potatoes on top. Make a white sauce from butter, flour and milk. Pour over potatoes. Salt and pepper to taste. Bake at 350 degrees for 45 minutes or until hot and bubbly.