Soak beans overnight according to package instructions. Discard bean water and rinse. Sauté meats to brown in this order: salt pork, sausage, pork shoulder, chicken. Remove to a plate after each batch is browned. Saute onion, celery, carrot until onion is translucent. Add garlic and saute another 30 seconds. Add beans, tomato paste, thyme, bay leaves and stock. Place browned meats on top. Slow Cook on low 10 hours, or on high 7 hours. When done, take out and break up the chicken and pork shoulder into chunks. Add bread crumbs and mix. Place meat back on top and let sit a few minutes.