Ingredients
1/2 cup butter, cubed1/3 cup all-purpose flour2 teaspoons salt, divided2 teaspoons pepper, divided4 cups whole milk7 large potatoes, peeled and thinly sliced2 medium onions, chopped8 cups shredded cheddar cheese
Preparation
In a large saucepan, melt butter. Stir in flour, 1 teaspoon salt and 1 teaspoon pepper until smooth. Gradually add milk; bring to a boil. Cook and stir for 2 minutes or until thickened and bubbly; set aside.
Combine the potatoes, onions, cheese, remaining salt and pepper. Place a third of the mixture in a greased 5-qt. baking dish; top with a third of the sauce. Repeat layers twice.
Cover and bake at 350° for 2-1/2 hours. Uncover; bake 30 minutes longer or until potatoes are tender.
