One of the vertebrae in my kitchen is making confit. Here a smaller lid is used in the bigger pot to ensure that the duck pieces are submerged. This is how I make it:
Love Apples' Duck Confit.
I usually make double this, but it looked obscene on the page and I couldn't bear it. This confit is therefore for 6 duck legs (2-2.5 kg/4.5-5.5lbs). Add gizzards and wings with the tips cut off if you have them.
The Confiting Fat. You can buy rendered duck fat, but it's best to make it at home. Commercially available fat is rendered at too high a temperature, and it effects texture and taste. To render your own, take about 4 kg duck skin, or 2 kg cavity fat; chop into a rough dice and place in a deep heavy ovenproof vessel (I use my Staub or Le Creuset) with about ½ cup of water. Set oven to 110C/225F/Gas Mark ¼; place in oven. It may be ready in 2 hours, or may take longer to fully render. Allow to cool enough to handle safely; strain. If using duck skin, reserve solids to crisp for another use.
This should yield about 7 cups of rendered duck fat, but it depends on the water content of the skin. I believe it will make enough, but it depends on the shape of pot you use to make the confit. I always think too much is better—so many uses, plus it freezes well.
Salting and Curing. For 6 whole duck legs use 16 generous tablespoons coarse sea salt alone, or with the addition of any or all of the following: 3 tablespoons peppercorns, crushed; 2 bay leaves, crumbled; 2 tablespoons juniper berries, crushed; 4 sprigs fresh (or 1 tsp dried) thyme; 2 small sprigs fresh rosemary, leaves chopped (or one healthy pinch dried and crumbled); and 2 cloves of garlic, crushed and chopped. I go through periods of using lots of herbs, to periods of using only austere bay, juniper, thyme, pepper to periods of finding salt alone the best thing. Rub salt or salt mix into duck pieces. Cover and chill. Commonly it's said that it should be allowed to cure refrigerated from 8 to 24 hours. I don't disagree, but I do note that there's a significant difference between 8 and 24 in terms of the saltiness of the final confit. And so if I intend to serve a whole leg per person, I allow only 8 hours of curing, while if it's for smaller pieces in a bigger context (such as for cassoulet), I let it go for longer. But usually I keep to 8 hours or so—it's sufficient yet doesn't overwhelm.
After curing time, rinse salt off under cold water, and pat duck pieces dry.
Confiting. Allow rendered duck fat to come to room temperature. Pour into a very heavy enamelled pot or heavy ovenproof crock. Slip duck pieces into it, making sure all pieces are submerged in fat. At this point you may add some whole garlic cloves or a head of garlic with the top sliced off and/or 1 or 2 cloves (as in clous de girofle, not garlic) Cook over a low flame/in slow cooker/in very low oven until fat reaches 90C/195F (it should take nearly an hour to reach temperature), and allow to cook for another 1 ½ or 2 hours, monitoring temperature periodically. It is ready when meat seems tender at the bone.
Remove duck pieces to a heat-proof glass jar or a crock. Pack tightly. Heat fat until small bubble form (well short of smoking point), and carefully ladle over duck pieces, making sure all pieces are covered in fat. Allow to cure refrigerated for at least one week. If you wish to keep for several months, seal in a further layer of home-rendered lard (lard is more dense than duck fat, and therefore seals with greater efficiency), and cover with parchment paper.
Pork shoulder, lamb shank, goose, and even turkey make for fairly fantastic confits, and this recipe suits well, and only needs to be adapted for cooking time.