Creamy Scalloped Potatoes

 

2 pounds potatoes (about 6 medium)

3 T. butter or margarine

3 T. flour

1 t. salt

¼ t. pepper

2 ½ c. milk

1 small onion, chopped finely (about ¼ cup)

1 T. butter or margarine

 

Peel potatoes and slice thinly.  Heat 3 T. butter or margarine in saucepan over medium heat until melted.  Add flour, salt and pepper.  Cook over low heat stirring constantly, until mixture is smooth and bubbly.  Remove from heat.  Stir in milk.  Heat to boiling, stirring constantly.   Boil and stir 1 minute.  Arrange potatoes in a greased 3 qt casserole dish, in 3 layers, topping each of the first two layers with ½ of the onion and 1/3 of the white sauce.  Top with remaining potatoes and sauce.  Dot with 1 T. margarine.  Cover and cook in 325 degree over for 40 minutes, or in a 350 degree oven for 30 minutes.  Uncover and cook until potatoes are tender, 60-70 minutes longer.  Let stand 5-10 minutes before serving.