How to Make It
Bring a large pot of water to a boil over high heat. Remove and discard the wilted outer leaves of the cabbage and dig out the core. Loosen as many leaves as possible: then slip the cabbage intro the boiling water and cook until the leaves begin to loosen, about 5 minutes. Remove the cabbage and rinse under cold running water. Carefully separate 12 of the outer, large leaves. Reserve the remaining cabbage for another purpose.
Meanwhile, bring a second pot of water to a boil, add 1 teaspoon salt and the 12 cabbage leaves and cook for 3 minutes. Drain, rinse and drain well in a colander.
Carefully trim the duck legs of excess fat. Bone each duck leg, leasing the meat with the skin in one piece. Lightly score the skin in a diamond pattern with a sharp knife. Remove as many thick tendons from the legs as possible without damaging the meat and refrigerate.
Preheat the oven to 425°. Crack the duck bones into small pieces, place in a heavy roasting pan and cook in the oven, turning once, until lightly browned, about 25 minutes. Add the onions, carrots and garlic cloves and continue to cook until brown, about 30 minutes longer. Scrape the bones and vegetables into a large heavy saucepan. Discard the fat from the roasting pan; place the pan over moderate heat, add 1 cup of cold water and bring to a boil, scraping up any browned bits from the bottom of the pan. Add this liquid to the pot along with enough water to cover. Bring to a boil over moderately low heat. Skim the surface and add the bouquet garni and white wine. Simmer, uncovered, for 30 minutes. Add the tomatoes and cook for 30 minutes longer. Strain the stock into a large saucepan, pressing on the vegetables and bones to extract all their juices. Skim off any grease from the top. Boil the stock over high heat, skimming occasionally, until reduced to 1 1/2 cups, about 45 minutes.
Put the bread cubes in a medium bowl. Pour the milk over the bread and let stand for 2 to 3 minutes, until soft. Press out and discard any excess milk. Add the ground pork, garlic, shallots, 1/2 teaspoon of the salt, 1/4 teaspoon of the pepper, the chives, parsley and nutmeg to the bread. Mash with a fork to blend well. Then work in the beaten egg. Cover and refrigerate the stuffing until firm, about 20 minutes.
In a small saucepan of boiling water, blanch the salt pork for 5 minutes. Drain and pat dry with paper towels. In a large ovenproof skillet, slowly cook the salt pork in its own fat over moderate heat until lightly browned, about 5 minutes. With a slotted spoon, transfer the salt pork strips onto paper towels to drain, leaving the fat in the skillet.
Place the apple in a small dish designed for microwave use. Cover and cook on high for 2 to 3 minutes, or until soft, (Alternatively, the apple can be steamed until soft.) Remove the skin and core; crush the apple with a fork to a smooth puree. Press through a sieve for finer texture if desired. (The recipe can be prepared to this point a day in advance. Refrigerate the cabbage, stock, stuffing, skillet fat and apple puree separately.)
About 2 hours before serving, preheat the oven to 325°. Season the duck legs with 1/4 teaspoon each salt and pepper. Heat the reserved fat in the skills over moderate heat until almost sizzling. Add the duck legs, skin-side down, and sauté until lightly browned, 2 to 3 minutes. Turn and sauté on the second side for 1 to 2 minutes. Drain the duck pieces on paper towels; reserve the fat in the skillet off heat. Cut each duck leg in half crosswise and let cool slightly.
Spread out the cabbage leaves and pat them dry; season them with 1/2 teaspoon each salt and pepper. Place 1 heaping tablespoon of the stuffing onto each cabbage leaf. Place a duck piece on top and cover with another heaping tablespoon of stuffing. Wrap the cabbage around the duck and tie with kitchen string in both directions like a package.
Pour out half the reserved fat in the skillet. Heat the remaining fat over moderate heat. Add the cabbage rolls and brown well on both sides, about 5 minutes per side. Remove to a plate. Drain off the fat and wipe out the skillet. Return the cabbage rolls to the skillet in a single layer. Reheat the stock to boiling; pour over the cabbage rolls. Add the salt pork strips and cover with a round of waxed paper and a lid or foil. Bake in the oven for about 1 1/2 hours, turning each cabbage roll midway, until the duck is very tender.
Transfer the rolls to a serving platter. Cut away and discard the string. Skim off any excess grease from the cooking liquid. Boil, if necessary, to reduce the sauce to 1 cup. Beat in the pureed apple, adjust the seasoning with salt and pepper, if necessary, and the lemon juice and pour the sauce over the cabbage. Decorate with parsley leaves and serve.