Wash the duck, dry thoroughly and cut into serving pieces. Set aside. In a deep saucepan or casserole bring the coconut milk to the boil; simmer for 5 minutes. Pour off half and set aside, then simmer the remaining milk for about 15 minutes. Add the duck and simmer 10 minutes. Drain the chilies and pound to a paste with the salt. Grind the peppercorns, caraway and coriander seeds together and pound with the chilies. Add the dried shrimp paste, cilantro root and leaves, lemon grass and lime and pound to a smooth paste. Stir into the duck and coconut milk, at first adding only half the paste; check the strength before adding the remaining seasoning paste. Add the reserved coconut milk, a large splash of fish sauce and basil. Simmer until the duck is tender and the sauce is thick and flavorful. Check the seasoning and serve with rice. Unused seasoning paste can be stored for several days in a covered jar in the refrigerator.