Combine the marinade ingredients in a large bowl. Place the
chicken legs in a zip-top bag. Pour in the marinade. Remove the air, and seal the bag. Refrigerate for a few hours or overnight.
Setup your grill, so you have a direct and indirect heat zone.
Place the chicken on the grill over medium heat. Cook for about 20 minutes, turning occasionally. If the chicken begins to char, move it to the indirect heat zone, as needed.
If preparing the boky choy, start cooking it at this point.
Combine the sauce ingredients in a pot and heat.
After the chicken has reached an internal temperature of 165F degrees, dunk each leg in the sauce. Return to the grill for 2-3 minutes.
Dunk again, and cook a few more minutes. Then, dunk one more time, and cook for 2-3 more minutes.
Sprinkle with sesame seeds and green onions.