For this recipe, the ducks are stuffed with whole kumquats, which are taken out of the cavity when the birds are done, then used to make a sweet, tangy relish that goes with the richness of the meat.
Because I have an irrational fear that my guests will hungry (even though it has never happened), I cook two ducks for four diners. But if you serve a few side dishes, you can stretch two ducks to serve six, or even eight if your guests are moderate eaters.
Chinese rose wine is somewhat of a misnomer, because it's not actually wine. Instead, it's a distilled spirit that's flavoured with roses. It has a high alcohol content (more than 50 per cent). If you can't find it, substitute brandy or cognac.
If the ducks have the head and neck attached, chop them off as close to the body as possible. Chop off the wing tips. (The wing tips and neck can be used to make duck stock, although you won’t need it for this recipe.)
Weigh each duck separately, then times the weight in kg by .005 – this is the amount of salt, in grams, you will need (if using pounds, use ½tsp per pound of duck). Weigh out the correct amount of salt, then sprinkle it over the duck, using more on the meaty parts (breast, legs and thighs) and less on the wings and back. Sprinkle some of the salt in the cavity of the bird. Put the ducks in a container, cover with cling film and refrigerate for at least eight hours.
Grate 10g (⅓oz) of the peeled ginger, preferably using a Japanese ceramic oroshigane (grater with fine teeth), or use a fine rasp-type grater. Put the grated ginger in a small saucepan and add the honey or maple syrup and the rose wine. Sprinkle in the five-spice powder (if you add it all at once, it tends to clump up). Bring to a simmer, then cool to tepid.
Rinse the kumquats and drain them in a colander. Divide the remaining peeled ginger into four even portions and lightly crush each piece with the side of a cleaver. Put one piece of ginger into the cavity of each duck, then add a cinnamon stick and one star anise. Stuff four kumquats into each duck cavity, then add one more piece of ginger and another cinnamon stick and star anise. Add more kumquats, packing them in so they are almost spilling out. You might not need all of them.
Use wooden toothpicks to “sew” up the flaps of skin hanging over the duck cavity: overlap the two pieces of skin, pierce the layers on one side with a toothpick, slide it under the layers and then out the other side. You will probably need to use three or four toothpicks for each duck, to prevent the kumquats from falling out.
Use pan coating to spray a roasting pan large enough to hold the ducks, or brush it very lightly with oil. Put the stuffed ducks breast-side up in the pan and brush them thoroughly with the honey or maple-syrup mixture. Turn the birds over so they are back-side up, and brush them evenly with the syrup mixture. Leave at room temperature for about two hours. Preheat the oven to 180°C (350°F).
Once again, brush the backs of the ducks with the honey or maple-syrup glaze, then slide the pan into the oven. Cook for 20 minutes, then take the pan from the oven and brush the backs once more with the glaze. Cook for 20 more minutes, then carefully turn the ducks over so they are breast-side up. Brush with the glaze and bake for 20 minutes before brushing again. Place the ducks back in the oven and bake for 20 more minutes (or longer, if the birds are larger than 1.3kg). Remove the pan from the oven and leave the ducks to rest at room temperature while making the kumquat relish.
Remove the toothpicks from the duck and take the kumquats from the cavity (discard the ginger, cinnamon and star anise). Roughly chop the kumquats (they will be hot, so be careful) and put them in a pan; if you like, you can remove and discard the seeds, although they are edible.
Quarter the shallots, thinly slice them, then put them in the pan and add the grated ginger. Put the mustard seeds in a small, unoiled skillet placed over a medium flame. Shake the skillet constantly until the mustard seeds are toasted and fragrant, then add them to the pan with the other ingredients. Stir in the sugar and vinegar.
Bring the mixture to a boil over a medium flame, then lower the heat and simmer for about 10 minutes, adding some water if the ingredients stick to the pan. Taste the relish and add more sugar and vinegar so the mixture has a sweet-tart flavour. Simmer for five more minutes, adding a little water, if necessary; the texture should be thick and jam-like. Transfer the relish to a bowl and serve with the duck.
For a casual meal, cut the ducks in half using poultry shears, and place each half on a dinner plate. For a more formal presentation, carve off the duck breasts and slice them, then lay them on a platter. Carve off the wings and legs. Cut the the legs between the joint, so there's a drumstick and thigh. Lay the pieces on a platter. Any juices on the carving board should be poured into a small bowl and served with the duck and the kumquat-ginger relish.