In a small sauce pan, soften butter and mix in flour.
Let sit for a minute.
Add all of chilly milk, stirring with a whisk.
Season with salt and cayenne.
Prepare dinner sauce on low till clean and boiling, stirring often with a whisk.
Scale back warmth and stir in cheese.
Place a half of the sliced potatoes in a calmly greased one quart casserole dish.
Pour half of cheese sauce over potatoes.
Repeat with second layer of potatoes and cheese sauce.
Sprinkle the remaining cheese on prime.
Prime with some paprika for coloration.
Bake uncovered for about 1 hour at 350°F.
