Anyone who hosts a holiday dinner will want to keep this make-ahead recipe close by. Layer the potatoes and cheese sauce in the casserole the night before.
1. Place potatoes and salt in saucepan. Add cold water to cover. Bring to a boil; simmer 8 minutes. Drain; rinse with cool water.Sauce:
2. In a saucepan, melt butter over medium heat. Add leeks; cook for 6 to 8 minutes or until softened.
3. Sprinkle flour over leeks and whisk to make very thick paste. In 2 additions, whisk in warm milk until smooth. Add salt, pepper, cayenne and nutmeg. Bring to a boil over medium heat, whisking occasionally. Remove from heat. Whisk in 1 1/2 cups cheese blend, reserving 1/2 cup.
4. Coat 13 x 9 x 2-inch baking dish with cooking spray. Layer half of potato slices in dish; spoon half the sauce over potatoes; spread to cover. Top with second layer of potatoes and sauce. Sprinkle with reserved cheese. Cover with foil; refrigerate until baking or overnight.To bake:
5. Heat oven to 375 degrees F. Remove foil from dish. (If taking dish directly from refrigerator, place in oven while heating.) Bake 20 minutes. Top with crackers. Bake 10 minutes, until crackers are lightly colored. Let stand 10 minutes.