Place chicken on cutting board and use a kitchen mallet, rolling pin or small sauce pot to flatten any thick ends. This step ensures even width and even cooking. Pour dressing into a large resealable plastic bag.
Place chicken in bag with dressing. Seal bag and refrigrate 30 min. to 1 hour to marinate.
Preheat barbecue to medium heat. Remove chicken from plastic bag and discard marinade. Place chicken on barbecue; cover with lid. Grill 6 to 8 minutes on each side or until cooked through.
Brush with barbecue sauce during last few minutes of grilling time.
Prep: 5 min. total 1 hour 21 minutes (incl. marinating).
Makes 4 Servings.