BLEND steak sauce and salsa. Place steak in glass dish; coat with 1/4 cup of the steak sauce mixture. Cover. Refrigerate 15 minutes to 1 hour to marinate, stirring occasionally.
COOK onion and green pepper in oil in large skillet on medium-high heat 3 minutes or until tender. Remove with slotted spoon; reserve. Cook and stir steak in same skillet 5 minutes or until cooked through. Add remaining steak sauce mixture, onion and pepper; cook until heated through.
PLACE steak mixture in tortillas; wrap. Serve with fajita toppings, if desired.