Potatoes Au Gratin
["8 medium potatoes, sliced and also peeled", "1 onion (large), cut in thin slices", "Cheddar cheese", "4 Tbsp. butter or margarine", "1 tsp. salt", "4 Tbsp. flour", "2 c. milk", "8 oz. or more Cheddar cheese, grated (mild)"]
["In saucepan, put butter or margarine, salt, flour and milk. Be sure to keep this smooth; I use a wire whisk.", "Add cheese. Bake at 350\u00b0 for about 45 minutes.", "Sprinkle paprika on top. Serves 8 to 10."]
["potatoes", "onion", "Cheddar cheese", "butter", "salt", "flour", "milk", "Cheddar cheese"]