To make scalloped potatoes with cheese, layer slices of potatoes into a 1-quart casserole dish with onions and seasoning, and cover them in separately prepared cheese sauce of butter, flour, salt, milk and cheddar cheese. Bake the dish in a preheated oven at 400 degrees Fahrenheit for about an hour and a half. You can use various types of cheese to experiment with the recipe, and the dish makes a great side for roast pork or beef.
To make the potato part of the dish, slice an onion into rings and four russet potatoes into slices 1/4-inch thick. Layer two potatoes worth of slices on the bottom of a 1-quart buttered casserole dish, cover them with the onions, and add the rest of the potatoes on top. Season these potatoes and onions with salt and pepper.
To make the cheese sauce, melt 3 tablespoons of butter over medium heat. Mix in three tablespoons of all-purpose flour and 1/2 teaspoon of salt, whisking continuously for one minute. Then, stir in the milk and cook the mixture until it thickens. At this point, add 1 1/2 half cups of cheddar cheese all at once, stirring the sauce until the cheese melts. Pour this sauce over the potatoes and onions, cover the dish with aluminum foil, and bake.