Rustic Au Gratin Potatoes

1. Preheat oven to 400 F. Spray a 13 X 9 casserole dish with nonstick cooking spray. Place sliced potatoes in prepared dish.

2. In a medium saucepan, melt butter over medium heat. Mix in flour and salt, and stir constantly with a whisk for one minute. Stir in the cream, milk and onion. Cook until mixture has thickened. Add cheese all at once and stir until melted, about one minute.

3. Pour sauce over potatoes, making sure that they are evenly covered. Season with additional salt and pepper to taste.

4. Cover dish with aluminum foil. Bake for 1 1/2 hours, removing aluminum foil for the last 20 minutes of baking.

Notes:
– In lieu of quartering and slicing potatoes by hand, you can peel and slice them with an apple peeler.
– If desired, 1 additional cup of milk can be substituted for 1 cup of heavy cream.