Spaghetti And Ham And Cheese Sauce

Ingredients:
- 1 lb. spaghetti
- small block Velveeta, cut in 1/4-inch squares
- 1/2 onion, diced
- 4 c. milk
- 1/2 stick margarine
- 2 (1/4-inch) slices ham, cut in 1/4-inch squares
- 1/4 c. flour

Directions:
- Cook spaghetti.
- Saute onions in butter.
- Add flour until butter is soaked up.
- Add milk and cheese.
- Add ham and stir constantly until sauce starts to thicken.
- Serve over spaghetti.