Rinse beans thoroughly, then soak for at least 2 hours but no longer than 12 hours.
Preheat oven to 350°F.
Drain beans and rinse under cold water. Fill a 4 1/2 quart Dutch oven with water and bring to a boil. Blanch beans in the boiling water for 7 minutes, then drain and run under cold water again. Set aside bowl.
In a blender, combine the onion, garlic, parsley, thyme, salt and 1/4 cup of water. Puree until smooth.
In the Dutch, oven sear pork belly cubes over medium heat until browned on all sides—about 5 minutes. Stir often to prevent burning. Remove and set aside.
Melt duck fat in the Dutch oven over medium heat, then cook the sausages, stirring frequently until brown, about 5 minutes. Remove the sausages and set aside. Add garlic/onion puree and reduce heat to low. Cook for 10 minutes, stirring regularly and scraping any pieces to meat stuck to the bottom.
Add the puree and the carrot to the beans, and mix until well-coated.
Transfer about 1/3 of the bean mix to the Dutch oven, enough to cover the bottom.
Layer the pork belly over the beans, then the sausages. Finally, place the duck legs on top and cover with the remaining beans. Season with nutmeg and a good grind of pepper. Add just enough stock to cover the beans. Reserve any remaining stock to add during the cooking process.
Bake uncovered until the cassoulet comes to a simmer on the sides and a crust begins to form, about 40 minutes. Reduce heat to 300°F, and cook for 1 hour 45 minutes, checking regularly to break the crust with the back of a spoon and ensure that the cassoulet remains moist. Add stock or water if necessary.
Remove the cassoulet from the oven and let rest for 15 minutes before serving. Place the Dutch oven at the center of the table and serve family style. Enjoy!
