Potatoes Au Gratin - cooking recipe

Ingredients

4 tablespoons butter
3 tablespoons flour
1/2 teaspoon dry mustard
1/4 teaspoon turmeric
1/2 teaspoon pepper
1 teaspoon salt
2 cups 2% low-fat milk
2 cups medium cheddar, shredded
1 tablespoon onion, finely grated
6 cups red potatoes or 6 cups gold potatoes, sliced

Preparation

Melt butter in a 2-quart saucepan.
Add flour and seasonings, stir or whisk until smooth. Whisk in milk and continue to cook on medium-low heat, stirring constantly for 5 minutes.
Turn off heat under saucepan. Add cheese and grated onion and stir until melted.
Wash and slice potatoes approximately 1/8 inch thick. Do not peel.
Place potato slices (and 1 cup sliced onion, if you choose) in a large 3-quart casserole. Note: if you use a smaller casserole, place it on a pizza pan or cookie sheet to catch any sauce that bubbles over.
Pour cheese sauce on top and fold into potato slices.
Bake at 375F for 45 minutes, stir gently, and return to oven. Bake for an additional 30-45 minutes, until potatoes are tender.