Soak the beans overnight with a generous amount of cold water to cover.

Drain the beans and place them in a large Dutch oven with the whole onion, bacon, carrots, celery, and herbs.

Cover by 2 inches with water and bring to a rapid boil over high heat.

Reduce the heat to low, cover, and simmer until the beans are tender, usually about 1-½ to 2 hours.

Place a fine-mesh strainer over a large bowl. Drain the beans, saving the liquid and vegetables.

Season the meat with salt, pepper, and herbs.

Heat the fat in the Dutch oven until smoking hot over high heat.

Brown the lamb and the pork on all sides, about 10 minutes per batch. Reserve the browned meat.

Add the diced onions and garlic to the pot and cook until soft, about 5 minutes.

Add the tomatoes and cook for 5 minutes more.

Return the meat to the pot, pour in the white wine and stock, and bring it to a boil.

Reduce the heat to low, cover, and simmer for 2 hours. Drain, reserving both the meat and cooking liquid.

Preheat the oven to 400°F.

In the same Dutch oven, spoon half the beans in the bottom of the pan.

Arrange the duck, pork, lamb, and sausage over the beans. Top with the remaining beans.

Pour in the reserved cooking liquid. The beans should be just covered with liquid.

Sprinkle half the breadcrumbs over the top and bake for two hours.

Sprinkle with half the remaining panko, and bake until brown and bubbly, about 20 minutes longer.

Serve from the pot, making sure each diner gets some of everything.