Coarsely crack black pepper.
Sprinkle half of the pepper over steak.
Rub pepper into meat, pressing with your hands.
Turn steak over.
Rub remaining pepper into other side of meat.
Place steak on the unheated rack of a broiler pan.
Broil 3 to 4 inches from the heat for 8 to 10 minutes or to desired doneness, turning once.
Thinly slice meat diagonally across the grain.
Spoon Mustard Sauce over beef slices.