Place lamb chops in a plastic bag; set in deep bowl. Combine cracked black peppercorns, green peppercorns, and white pepper. Set aside.
For marinade, combine half of the pepper mixture, the wine, oil, rosemary, and garlic. Pour mixture over lamb. Seal bag. Marinate in the refrigerator for at least 6 hours or up to 24 hours, turning bag occasionally to distribute marinade.
Place chops on the unheated rack of a broiler pan. Broil 3 inches from the heat for 5 minutes. Turn and broil for 4 minutes more or until juices run clear. Spread mustard on one side of chops and pat the remaining pepper mixture into the mustard. Broil 1 minute more or until desired donesness. Makes 4 servings.