In large bowl combine potato wedges, onion, oil, parsley, garlic powder, salt and pepper. Place in a foil broiler pan in single layer. Cover with second foil pan to form packet. Reinforce sealed edge of packet with foil. Place on grill over medium heat; cook 40 to 50 minutes or until tender, shaking the packet periodically and turning upside down halfway through grilling. Remove cover; top with cheese. Cover, cook 3 to 4 minutes more until cheese melts. Note: To make broiler pan packet, invert one broiler pan over filled broiler pan, overlapping slightly. Fold top of one short end down to seal; fold bottom of other end to seal.