TOSS steak with 2 Tbsp. of the steak sauce; let marinate for at least one hour. Meanwhile, combine remaining 2 Tbsp. steak sauce, the barbecue sauce and mustard; set aside to use for basting when grilling skewers.
To Freeze: Freeze in freezer safe container.
To Reheat: PREHEAT grill to medium-high heat. Thread steak onto eight long soaked wooden or metal skewers. GRILL skewers 6 min. or until steak is cooked through, turning after 3 min. and brushing generously with the extra barbecue sauce mixture.