Preheat oven to 350°F.\n\n1. Cook macaroni noodles as directed on package.\n2. While macaroni is cooking, melt butter in 3-quart saucepan over low heat. Stir in flour, salt, pepper, dry mustard, and Worcestershire sauce. Cook over low heat, stirring constantly, until mixture is smooth and bubbly; remove from heat.\n3. Stir in milk. Heat to boiling, stirring constantly. Boil and stir 1 minute.\n4. Stir in cheese. Cook, stirring occasionally, until cheese is melted.\n5. Drain macaroni. _Gently_ stir macaroni into cheese sauce.\n\nPour into _ungreased_ 2-quart casserole. Bake uncovered for 20 to 25 minutes or until bubbly.