Remove a bit of the skin from the ends of each leg, then make diamond incisions in the skin without cutting through the meat. Place the legs in a flat-bottomed container and set aside.
In a medium bowl, whip the rest of the ingredients, with the exception of the bok choy. Pour this marinade over the duck legs and then let them marinate for 12-24 hours in the refrigerator, turning them halfway through.
Preheat the barbecue to medium heat, shutting off the central burner to allow indirect cooking. Place the legs on the barbecue grill over the element that was shut off. Place a small aluminum container below the grill and above the central burner to catch any fat that drips from the legs.
Close lid and grill the legs for about 50 minutes, turning them frequently. Take care to avoid any flames. If it starts flaming, move the meat and then put it back on the grill. Cover the legs with a sheet of aluminum foil to prevent drying and continue cooking for about 70 minutes. Add the bok choy during the last 2-3 minutes of cooking, uncovered.
Remove the legs and bok choy from the grill and set aside the legs for 5 minutes, loosely covered with a sheet of aluminum foil.
Serve one leg per plate on top of the grilled bok choy. Boil the rest of the marinade for 60 seconds and then pour over each serving. Serve with sesame rice noodles.
Recipe developed by Nicolas Vallée, professional chef