Packed with ham and taters, this casserole brings a warm, filling feeling any day of the week.
Preheat the oven to 350 degrees. Let's rock.
Thinly slice the potatoes with a mandolin to measure about 4 cups worth. Heat 3 tablespoons of butter in a saucepan on low heat until they've melted. Mix in the flour, salt, and pepper. Cook on low heat and whisk constantly until the mixture turns smooth and bubbly. Gradually mix in the milk, keeping the consistency thick before adding the next bit of milk. Bring it to a boil again while whisking constantly. Slowly add the shredded cheese a little at a time.
Put the potatoes in a greased 2-quart casserole in layers, topping each layer with equal amounts of sauce, onion and cubed ham. Dot the top layer with a tablespoon of butter. Cover the dish and bake it in the prepped oven for 30 minutes. Uncover and continue baking until the potatoes are tender, 60-70 minutes longer. Let stand 5-10 minutes before serving.