Cut the steaks crosswise into 1" wide strips; reserve. Cook and stir onion in oil in large nonstick skillet over medium-high heat 3 minutes or until lightly browned. Remove and keep warm. Add beef strips (1/2 at a time) to skillet; cook and stir 2 to 3 minutes. Add barbecue sauce and onions; heat until hot. Place an equal amount of the beef mixture over corn muffins.
