In a mixing bowl, stir together the duck and pancetta with your hands until well mixed. Add pepper, salt and white wine and mix until well blended, again with your hands. You must move quickly here or your body temperature could change the texture of the fat.
Set up the sausage stuffer and place the casing over the funnel feeder. If you do not have a sausage stuffer, form the sausage into 1/4-pound logs by hand, and be careful handling them. Stuff the sausage into the casings, twisting every 3 1/2 to 4 inches so that each sausage is about 4 ounces, and form 22 to 25 sausages. Prick them all over with a needle and set aside in a cool place until ready to cook.
In a 12 to 14-inch skillet, heat the olive oil over medium heat and add sausages. Cook until golden brown, about 7 minutes a side, then add the onions and garlic. Cook until soft and golden, about 8 to 9 minutes. Remove the sausages and set on a plate. Stir in the tomato paste and cook for 5 or 6 minutes. Add the red wine and stock, scraping the bottom of the pan with a wooden spoon to release any browned bits into the mixture. Return the sausages to the pan. Cook over medium heat covered, for 15 minutes, turning occasionally. Stir in the parsley and serve immediately.
In a large, heavy-bottomed saucepan, heat the oil over high heat until smoking. Add all the chicken parts and brown all over, stirring to avoid burning. Remove the chicken and reserve. Add the carrots, onions, and celery to the pot and cook until soft and browned. Return the chicken to the pot and add 3 quarts of water, the tomato paste, peppercorns, and parsley. Stir with a wooden spoon to dislodge the browned chicken and vegetables bits from the bottom of the pan. Bring almost to a boil, then reduce heat and cook at a low simmer until reduced by half, about 2 hours, occasionally skimming excess fat. Remove from heat, strain, and press on the solids with the bottom of a ladle to extract out all liquids. Stir the stock to facilitate cooling and set aside. Refrigerate stock in small containers for up to a week or freeze for up to a month.
Yield: 1 1/2 quarts