An easy scalloped potato recipe is Betty Crocker's Scalloped Potatoes, which calls only for potatoes, butter, milk, flour and onion. To make it, cook 1 minced onion in 3 tablespoons of butter until it softens, and then add 3 tablespoons of all-purpose flour, 1 teaspoon of salt and 1/4 teaspoon of pepper, stirring continuously. Once the mixture bubbles, stir in 2 1/2 cups of milk, and heat the mixture until it starts to boil. Pour it over 6 sliced potatoes.
Finish by sprinkling 1 cut tablespoon of butter over the potato and sauce mixture, and bake it covered for 30 minutes at 350 degrees Fahrenheit. Remove the cover, and continue to cook for another 60 to 70 minutes. Serve the scalloped potatoes after 10 minutes.
Another recipe calls for cheese. Arrange potato slices along the bottom of a greased casserole dish, and top them with cheddar cheese slices, sprinkled flour, and salt and pepper to taste. Repeat the layers until using 8 potatoes, 14 slices of cheese and 1/2 cup of all-purpose flour. Pour 1 cup of skim milk over everything, and cover the dish with foil. Bake the scalloped potatoes at 350 F for 45 minutes, remove the foil and continue baking until the cheese starts to brown.