Step 1Soak the beans in water overnight. The next day, when you're ready to cook, first allow the duck confit to soften in the bag in a warm water bath or on a warm stove so it's easier to pull apart and separate out the fat.
Step 2Wrap the parsley, thyme, bay leaves and peppercorns in cheesecloth and tie it with kitchen twine to make a bouquet garni. Drain the beans and put them in a medium pot with the bouquet garni and the onion and enough water to cover by about 2 inches.
Step 3Bring to a boil, then reduce the heat and simmer, skimming any froth, for about 1 1/2 to 2 hours, or until the beans are soft; add water if necessary to keep beans fully submerged. When the beans are cooked, remove the bouquet garni and the onion, discarding the bouquet garni and reserving the onion. Set the pan with the beans and cooking liquid aside. Place the onion in a blender with one-half cup chicken broth and one-half cup cooked beans. Process until smooth. Set aside.
Step 4Blanch the kale in lightly salted water, for about four minutes; drain, squeeze out the excess liquid and coarsely chop.
Step 5In a medium saucepan, cook the onions, carrots and celery together in 2 tablespoons duck fat over low heat until the vegetables start to soften, about 5 minutes. Add the garlic and cook 5 minutes more.
Step 6With a fork or your fingers, coarsely shred the duck and add it to the pot with the beans. Add the mirepoix (carrots-onions-celery mix), remaining chicken broth, kale, onion-bean puree and salt and pepper. Cover and simmer for 30 minutes (or longer) to combine flavors.
Step 7Brush the baguette slices with the duck fat, using olive oil if you run out of duck fat. Broil the slices until golden. Grind black pepper over the toasted slices. Divide the soup among serving bowls. Place two slices baguette on each serving.