Elbow macaroni is baked with a creamy sauce of sharp Cheddar cheese, American cheese, milk, butter, onion, and dry mustard. You can top this dish with more cheese and bread crumbs, if desired. July 9, 2021July 9, 2021 Elbow macaroni is baked with a creamy sauce of sharp Cheddar cheese, American cheese, milk, butter, onion, and dry mustard. You can top this dish with more cheese and bread crumbs, if desired.