Scalloped Potatoes

From Betty Crocker

3 tbsp butter
2 lbs russett potatoes (about 6 medium)
3 tbsp flour
1 tsp salt
1/4 tsp pepper
2 1/2 c milk
1 onion, finely chopped
1 tbsp margarine or butter

Preheat oven to 350º.

Cut potatoes into thin slices to measure about 4 cups.

Heat 3 tbsp butter in saucepan over low heat until melted. Blend in 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 greased 2-qt casserole in 3 layers, topping each of the first two layers with 1/2 of the onion and 1/3 of the white sauce. Top with remaining potatoes and sauce. Dot with 1 tbsp butter. Cover and cook in oven for 30 minutes. Uncover and cook until potatoes are tender, 60 to 70 minutes longer. Let stand 5 - 10 minutes before serving.

Makes 6 servings.