In a large pot,heat the olive oil and cook the onion and garlic until lightly coloured. Add the drained haricot beans,the carrots,celery,bundle of herbs and kaiserfleisch (if you are using pork belly,first brown the pieces in a little oil in a pan). Cover with cold water and bring to the boil. Skim off any surface scum and set the heat to a moderate simmer. Cook for 1 - 1 1/2 hours until the beans are tender. Remove the herbs. Strain,reserving the stock and season with salt and pepper to taste.
Cut the duck in quarters,off the bone. Sprinkle with salt and a little olive oil. Place the duck,skin side down,on a rack,with a tray under it to collect and reserve fat for later. Grill (under medium heat) for about 10-15 minutes,basting once with the juices then turn over and grill for 10 minutes or until the skin is crisp and brown. Cut pieces in half.
In a pan with a little olive oil,gently brown the pieces of pork sausage.
To assemble:Choose a deep,wide enamel or stoneware casserole dish.
Preheat oven to 170C.
Layer half of the bean,vegetable and kaiserfleisch mix in the bottom of the casserole dish. Place half of the wine,herbs,chopped tomato,duck and sausage on top and cover with the rest of the mix. Finish with the last of the duck and sausage,tucking them into the beans a little,then pour over the reserved stock. There should be just enough liquid to almost cover the beans (if there isn't,add a little water).
Sprinkle the breadcrumbs in a thick layer on top and drizzle them with 3-4 tablespoons of the reserved duck fat. Bake uncovered for about 1 1/4 hours,until the crumbs have formed a firm,golden crust.
To serve
Serve directly from the pot with a sprinkle of chopped parsley.