Instructions

1. On the first day: Heat the oven to 250°. Rinse the duck legs and pat dry with paper towels. Arrange in a 4-qt. Dutch oven and season generously with salt. Pour the duck fat over the legs along with 15 garlic cloves, 1 tablespoon peppercorns, and 3 bay leaves. Transfer the pot to the oven and bake until the duck is very tender, about 3 hours. Remove the pot from the oven and let the duck legs cool. Lift the legs from the fat and reserve 1⁄4 cup duck fat; save the rest of the fat for another use. Wrap the duck legs in plastic wrap and refrigerate overnight.
2. On the second day: In an 8-qt. Dutch oven, melt the 1⁄4 cup reserved duck fat over medium-high heat. Unwrap the duck legs and add to the pot, skin side down. Cook the legs until the skin is crisp and golden, about 7 minutes. Remove the duck legs from the pot and transfer to a bowl. Add the pork sausages to the pot, and cook, turning, until golden brown, about 5 minutes. Transfer the sausages to the bowl and return the pot to the heat.
3. Add the Morteau sausages to the pot and cook, turning, until golden brown, 5 to 6 minutes. Remove the sausages from the pot and transfer to the bowl with the duck legs. Add the pork belly to the pot and cook, turning once, until golden brown on the outside, 8 to 10 minutes. Transfer the belly to the bowl and return the pot to medium heat.
4. Add the remaining garlic cloves and the onions to the pot and cook, stirring, until soft, about 5 minutes. Stir in the carrots and cook for another 2 minutes. Add the flour and cook, stirring, for 2 minutes more. Tie the remaining 3 bay leaves, the thyme, and rosemary with kitchen twine and add to the pot along with the tomatoes. Return all the meats to the pot and pour in the wine. Bring to a boil, reduce the heat to low, and cook, stirring occasionally, until the pork belly is tender and the duck legs are falling off the bone, about 2 hours. Using tongs, transfer all of the meat to a bowl and discard the tied herbs. Using an immersion blender or working in batches with a stand blender, blend the vegetables and tomatoes to thicken the sauce and then return the meat to the pot.
5. Meanwhile, in a large pot of boiling salted water, cook the beans until just tender, about 40 minutes. Drain the beans and then stir into the pot and simmer for another 5 minutes. Remove the pot from the heat and let the cassoulet cool. Cover the pot and refrigerate overnight.
6. On the third day: Remove the cassoulet pot from the refrigerator and heat over low heat until the ingredients are warmed through. Remove the meats from the pot and cut the duck legs in half, the sausages into 1-inch pieces, and the pork belly into 1⁄2-inch-thick slices. Ladle the stew and beans into bowls, top with some of the meat, and serve with a baguette for soaking up the sauce.