Make sure the skin is thoroughly dry, as soggy duck skin will never become crisp. Leave the bird unwrapped in a cool and dry place for a couple of hours before roasting to let the skin dry out. Prick the well-dried skin all over with a skewer or fork, being very careful not to pierce the flesh, then rub the bird with fine sea salt.
Weight the duck and calculate the cooking time, allowing 40-50 minutes per kg. Stand it on a rack in a baking dish. Preheat the oven to 220 degrees C and roast the bird for the first 30 minutes, then turn down the heat to 180 degrees C and complete the cooking. Drain the fat from the baking dish at 20-minute intervals so that it does not burn.
** Asian Online Recipes