I made this dish while my friends from Amsterdam were in town for a visit. My friend, Andrew assisted me in the kitchen as my Sous Chef. To get into character, I made him say "Yes, CHEF!" whenever I gave an order. Gordon Ramsay ain't got nuthin' on me.
Preheat oven to 350 degrees. Prepare a long, medium depth casserole dish by greasing the sides and bottom with butter. Peel the potatoes and slice them thin, about 1/8" inch thick. Wash the slices in a bowl of cold water. Drain and set aside.
Make a Bechamel Sauce: heat 4 TBSP of the butter over medium heat in a saucepan. Add the flour and whisk until combined. Slowly add the milk, stirring constantly. Heat this mixture until it begins to thicken. Now add the cheese a handful at time, waiting before the last handful is completly incorporated before adding the next.
Layer the dish:
Bake in the oven for about 45 minutes. Remove from oven and let set about 5 minutes before serving.