potatoes
chopped onions
1 pkg. shredded sharp cheese

Sauce:

1 c. potato water
1 c. milk
1 tbsp. flour
1 tbsp. butter

Mix flour and butter, then add potato water and milk. Stir until thick. Slice potatoes, partly cook not too done. Then fill casserole with layer of potatoes, layer of chopped onions and layer of shredded sharp cheese. Pour sauce over potatoes.

Bake at 350°F to 400°F for about 35 or 40 minutes.