Rub pepper over both sides of steaks. Refrigerate for 15 minutes. In an ungreased skillet, brown steaks on both sides over medium-high heat. Reduce heat to medium; add butter and garlic; cook for 4-6 minutes, turning steaks once. Add Worcestershire sauce; cook 4-6 minutes longer, turning once, or until meat reaches desired doneness (for medium-rare, a thermometer should read 135°; medium, 140°; medium-well, 145°). Remove steaks and keep warm.
Combine wine or broth, mustard and sugar; add to the pan. Stir to loosen browned bits. Combine cornstarch and water until smooth; add to pan. Bring to a boil; cook and stir for 2 minutes or until thickened. Serve with the steaks.
Top loin steak may be labeled as strip steak, Kansas City steak, New York strip steak, ambassador steak or boneless club steak in your region.