1 lb. boneless beef sirloin steak, thinly sliced
1/4 cup A.1. Original Sauce, divided
1/4 cup KRAFT Original Barbecue Sauce
1 tsp. GREY POUPON Dijon Mustard
Toss meat with 2 Tbsp. of the steak sauce; let stand 10 min. to marinate. Meanwhile, combine remaining 2 Tbsp. steak sauce, the barbecue sauce and mustard; set aside. Preheat grill to medium-high heat. Thread meat onto eight long metal or soaked wooden skewers. Grill skewers 6 min. or until meat is cooked through, turning after 3 min. and brushing frequently with the barbecue sauce mixture.