Butter large baking dish. Place layer of sliced potatoes in bottom. Crumble hamburger over potatoes. Cover with onion slices. Continue layers until desired amount. Sprinkle the top with hot sauce. Mix 1 can tomato soup with 1/2 can water. Pour into casserole. Top with slices of cheese. Cover with foil. Bake at 350 degrees for 1/2 to 1 hour.