Rinse duck and dry. Bend leeks and insert into duck cavity.
Stuff in also 1 whole onion and 1 piece ginger.
Put duck in a bowl and add the rest of the ingredients. Let it marinate for 10 minutes.
Drain duck and save marinade. In a large casserole, heat cooking oil, about 1 cup and brown duck.
Remove excess oil leaving about 1/4 cup.
Return duck to casserole. Add marinade and 1 cup water.
Simmer over low fire till tender about 2 hours, turning duck once.
Toward the end of cooking turn up the heat to thicken sauce.
Slice and serve with steamed rice.