PREHEAT barbecue to medium heat. Pierce both sides of chops several times with fork; place in shallow dish. Combine dressing and mustard. Pour half of the dressing mixture over chops; cover dish.
REFRIGERATE at least 15 min. to marinate. Set remaining dressing mixture aside for later use. Remove chops from marinade; discard marinade.
GRILL chops and vegetables 7 to 8 min. on each side or until chops are cooked through (160ºF) and vegetables are crisp-tender, brushing occasionally with the reserved dressing mixture.