1. Prep charcoal grill with medium-hot coals or heat gas grill to medium-high.
2. Using 12-inch-wide heavy-duty aluminum foil, cut 4 pieces 32 inches long; fold each piece in half to make a 16 x 12-inch rectangle. Generously coat foil pieces with nonstick cooking spray.
3. In a large bowl, stir together cumin, coriander, salt, oil and grated ginger. Rub half of this mixture over chicken; set aside. Stir lime juice into remaining mixture. Add peaches, sweet potato, pepper and scallions; toss to coat completely. Evenly place peach mixture on one half of each foil piece. Top each with seasoned chicken.Create a packet:
4. Fold second half of foil over chicken and vegetables. Tightly seal sides and front edges, leaving space for steam to build. Place foil packets on grill rack; grill 25 minutes. Open packets carefully; transfer contents to 4 serving plates.