PLACE THE BEANS IN COLD WATER and soak overnight. The next day, place a heavy pot on the stove over medium heat and cook the duck pieces on both sides to render some of the fat. This takes about 15 minutes total. Remove the duck and set aside. Increase heat to high and add the pork. Brown well, remove from the pot and set aside. Brown the lamb. Remove and set aside. Preheat oven to 150ºC . Pour off and discard most of the fat, leaving just about 3 tablespoons in the pot. Lower heat to medium and add the onions. Cook, stirring, until onions soften, about 7 minutes. Add drained beans, bacon, garlic and herbs and replace the duck, pork and lamb. Add 4 cups water, cover and place in the oven for 2 hours. Add the sausages and salt as desired. Replace in the oven another hour. Remove herbs in cheesecloth. When it's time to serve dinner, place the casserole on the table.