Bring the kidney beans to a boil in a large pot with plenty of salted water. Remove from the heat, cover and set aside for 1 hour.
In a large casserole or Dutch oven, heat the olive oil over high heat. Season the pork well with salt and pepper and sear on all sides, working in batches if necessary, and remove the meat when it is browned. Add the speck, sage, parsley, and garlic and saute for 5 minutes before returning the meat to the casserole.
Drain the beans and add them to the casserole with the stock and the sauerkraut and bring to a simmer. Cook the mixture slowly for 45 minutes, or until the pork is very tender and the beans are cooked through.
Slowly sprinkle the polenta over the stew and stir constantly for 10 minutes, or until the polenta has expanded. Season with salt and pepper, to taste, and serve.
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.