Mix 1/2 cup dressing and the garlic in shallow glass or plastic dish or resealable plastic food-storage bag. Add pork; turn to coat with marinade. Cover dish or seal bag and refrigerate at least 2 hours but no longer than 12 hours.
Heat coals or gas grill for direct heat. Mix remaining ingredients except cheese in square aluminum pan, 9x9x2 inches.
Remove pork from marinade; reserve marinade. Cover and grill pork and pan of vegetables 4 to 5 inches from medium heat 15 to 20 minutes, brushing pork occasionally with marinade and turning once, until pork is slightly pink in center and vegetables are crisp-tender. Stir vegetables 2 or 3 times during grilling. Discard any remaining marinade.
Cut pork into slices. Sprinkle cheese over vegetables.