1In shallow glass or plastic dish or resealable freezer plastic bag, place shrimp and dressing. Cover dish or seal bag; refrigerate 30 minutes.
2Heat gas or charcoal grill. Remove shrimp from marinade; reserve marinade. Thread shrimp, onion, bell pepper, tomatoes and mushrooms alternately on each of 4 (15-inch) metal skewers, leaving 1/4-inch space between each piece.
3Place kabobs on grill over medium heat. Cover grill; cook 6 to 8 minutes, turning frequently and brushing several times with marinade, until shrimp are pink. Discard any remaining marinade.