Combine first 3 ingredients in a small bowl; rub both sides of beef with pepper mixture. Place beef on a broiler pan coated with cooking spray; broil 5 minutes on each side or until desired degree of doneness. Set aside; keep warm.
Place a medium nonstick skillet coated with cooking spray over medium-high heat. Add onion to skillet; cover and cook 5 minutes, stirring occasionally. Remove onion from skillet; set aside, and keep warm. Add wine to skillet, scraping pan to loosen the browned bits. Cook over medium-high heat until reduced to 1/3 cup (about 1 minute), and stir in steak sauce. Spoon wine sauce over steaks, and top with onion.