1. Preheat grill to 350° to 400° (medium-high) heat. Combine garlic and next 5 ingredients. Reserve 3 Tbsp. garlic mixture. Pour remaining garlic mixture into a large shallow dish; add peppers, turning to coat. Cover and chill 15 minutes, turning once. Remove peppers from marinade, reserving marinade for basting.
2. Grill peppers, covered with grill lid, 8 to 10 minutes or until peppers blister and are tender, turning occasionally and basting with marinade.
3. Preheat broiler with oven rack 4 inches from heat. Combine chicken and peas with reserved 3 Tbsp. garlic mixture. Place peppers in a single layer on a lightly greased rack in an aluminum foil-lined broiler pan. Quarter cheese slices. Top each pepper with chicken mixture and one cheese quarter.
4. Broil 4 to 5 minutes or until cheese is melted. Remove from oven, sprinkle with cilantro, and serve immediately.