-Let sit for a minute.
-Add all of cold milk, stirring with a whisk.
-Season with salt and cayenne.
-Cook sauce on low until smooth and boiling, stirring occasionally with a whisk.
-Reduce heat and stir in cheese.
-Place a half of the sliced potatoes in a lightly 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 top.
-Top with some paprika for color.
-Bake uncovered for about 45 mins at 350°F.