Whisk together the soy, vinegar, honey, chili paste, ginger and garlic in a bowl and divide the mixture in half. Add 1 half to a large baking dish, then add the chicken, turning to coat. Cover and let the meat marinate in the refrigerator for at least 4 hours or up to 8 hours. Add the green onions, sesame oil, black pepper and sesame seeds to the remaining half of the mixture. Reserve it as a dipping sauce for the finished chicken.
Light a grill, making sure to include a zone of indirect heat.
Remove the chicken from the marinade and put it over the charcoal, skin side down. Grill until the skin is golden brown and crisp, about 10 minutes. Relocate the chicken to the indirect heat zone, lower the cover and grill until cooked through. Remove the chicken from the grill to a cutting board and carve. Arrange the chicken on a serving platter and serve wrapped in tortillas, if desired, with dipping sauce on the side.