Thaw duckling, if frozen.
For sauce, in a small mixing bowl combine soy sauce, mustard, wine vinegar, garlic, and ginger.
Rinse duckling quarters and pat dry.
Cut wing tips and excess fat from duck and discard.
Pierce duck skin in several places with a fork.
Place duck quarters, skin side up, in center of the cooking grill.
Grill 1 1/4 to 1 1/2 hours or till a meat thermometer inserted into thickest part of thigh registers 180Â°F (82Â°C) and the juices run clear, brushing generously with the sauce several times during the last half of grilling.
Note: Save yourself some work.
Ask your butcher to cut the duckling into quarters for you.