Cook macaroni according to package directions; drain.
In a large bowl, combine the soup, milk, chives, mustard and hot pepper sauce.
Stir in macaroni and cheese.
Spoon into a greased shallow 2-qt. baking dish.
Combine bread crumbs and butter; sprinkle over the top.
Bake, uncovered, at 400° for 25-30 minutes or until heated through and bubbly.