3 tablespoons butter
3 tablespoons all-purpose flour
1 teaspoon salt
1 teaspoon pepper
1 1/2 cups milk
2 cups  cheddar cheese, shredded (sharp works best)
5 medium potato, peeled and sliced
Preheat oven to 375 F.
In 2-quart saucepan over medium heat, in hot butter,  Stir in flour, pepper and salt until blended.
Gradually stir in milk and cook, stirring constantly, until mixture thickens slightly.
Remove saucepan from hear; stir in 3/4 cup shredded cheese.
In shallow casserole dish, arrange half of the potato slices
Pour 1/3 of the sauce on top then  sprinkle with 1/3 of remaining sherreded cheese; repeat.
Top with remaining cheese.
Bake, covered 45 minutes.
Uncover and bake 15 minutes longer or until potatoes are tender and slightly golden brown on top.
Can use different flavored cheeses or add your favorite vegtables or bacon as well for variation.