Over an open flame, roast the hatch, poblano, serrano and Anaheim chile peppers. Roast until the skins are charred and black all over, 2 to 3 minutes per side. Remove chiles from the flame and immediately place in a large bowl and cover with plastic wrap. Set aside and allow to steam for 8 to 10 minutes. Once the peppers have cooled, scrape away and discard the charred skin, then remove the stems and seeds. Finely dice the flesh and set aside.
In a small bowl, combine the milk and panko and set aside. In a medium mixing bowl, combine the ground turkey, onion, parsley, garlic, eggs, cumin, salt, black pepper, cayenne, panko-milk mixture and diced peppers. Mix all the ingredients together. Using your hands, shape the mixture into golf ball-sized meatballs, about 3 ounces each. Evenly space the meatballs on a baking sheet and place into the oven. Bake until firm and browned, 12 to 14 minutes.
Place the meatballs on a large platter, garnish with cilantro and serve.