Creamy Scalloped Potatoes
["2 lbs potatoes (about 6 medium)", "4 T margarine or butter", "3 T flour", "1 t salt", "1/4 t pepper", "2 1/2 c milk", "1 small onion, finely chopped (about 1/4 c)"]
["Cut potatoes into thin slices to measure about 4 cups. Heat 3 T margarine in saucepan, until melted.", "Blend in flour, salt and pepper.", "Cook, stirring constantly, until smooth and bubbly; remove from heat. Stir in milk.", "Heat to boiling, stirring constantly.", "Boil and stir 1 minute."]
["potatoes", "T", "flour", "salt", "pepper", "milk", "onion"]