Remove crusts from bread; cut bread into 1-in. cubes. Place in a greased 8-in. square baking dish. , In a small skillet, brown the sausage over medium heat until no longer pink; drain. Sprinkle the sausage and cheese over bread cubes., In a small bowl, whisk the eggs, milk, mustard, salt and pepper. Pour over the sausage and cheese. Bake at 350° for 30 minutes or until puffed and golden.