2 lb. potatoes
1 sm. onion, thinly sliced
1/4 c. flour
1 tsp. salt
3 tbsp. butter
1/2 c. milk
1/4 tsp. pepper
1 (10 oz.) can cream of mushroom soup
4 slices American cheese

Peel and thinly slice potatoes. Put half of the potatoes in a greased crock pot; top with half of the onions, flour, salt and pepper. Add remaining potatoes, onions, flour, salt, pepper, all the soup and milk and butter. Cover and cook on low 7-9 hours, or high 3-4 hours. Add cheese 1/2 hour before serving.