Preheat oven to 400 degrees. Spray a 9 x 13 casserole dish with cooking spray and set aside.

2.Layer the sliced potatoes in the casserole dish. (See photo)

3.In a medium saucepan, melt butter over low to medium heat. Mix in flour. Stir constantly for one minute. Slowly stir in milk and cream. Cook until mixture has thickened. Add salt and pepper and stir.

4.Stir in cheese and continue stirring until melted.

5.Carefully pour cheese sauce over potatoes. Cover the dish with aluminum foil.

6.Bake 1 hour. After the hour, remove foil and bake for another 20-30 minutes. The casserole will probably bubble a little and the potatoes will brown on top.

7.Let cool on wire rack for just about 5 to 10 minutes. Then, serve these cheesy gems!