Preheat oven to 350 degreees. In a saute pan, melt butter and whisk in flour, salt and pepper to taste* at medium heat. Continue to stir/whisk regularly while it comes to a boil and give it another couple of minutes to thicken nicely. Stir in the soup and half the cheese (adding it all at once makes it too thick to stir). Gently fold 1/2 of the potato slices (1 20-oz. package) to coat them with the cheesy sauce. * If not using Taco Cheese (a combo of Colby & Monterey Jack with seasoning already in the package), you will need to add some additional spices in to jazz it. Add in the rest of the cheese and stir until cheese is melted. Grease a casserole dish 10x13 or 11x13 and empty the other package of plain potatoes into the dish. Pour the cheesy glop of potatoes on top. Cover with Foil Heat for 20-30 minutes at 350...to heat it through. Remove Foil and heat for an additional 10 minutes for some browning to occur. Hearty appetites can add a dollop of sour cream or even guacamole.