GRILL DIRECTIONS: Heat grill. In small saucepan, combine jam and vinegar. Cook over medium heat until jam is melted, stirring constantly. Remove from heat.
Rub pepper onto both sides of each steak. When ready to grill, oil grill rack. Place steaks on gas grill over medium heat or on charcoal grill 4 to 6 inches from medium-high coals. Cook 8 to 12 minutes or until of desired doneness, turning once.
To serve, spread steaks with blackberry mixture; Top with berries.