Place beans, bacon or ham hocks, water and celery salt in heavy kettle. Bring to boil; cover and simmer about 2 1/2 hours or until beans are thoroughly tender. Remove bacon or ham hocks; set aside. Drain beans and reserve along with meat and cooking liquid. There should be about 6 cups of beans and 4 cups of liquid. Add enough broth to make 6 cups liquid. Combine the beans with liquid in large bowl. Heat oil in heavy kettle; add peppers, onions, garlic and cumin. Cook, stirring, until onions are wilted. Add tomatoes and vinegar. Let simmer about 15 minutes. Meanwhile, remove and discard skin from bacon, or skin and bones from ham hocks. Chop ham; set aside. Add beam mixture to cooked tomato mixture. Add chopped meat and coriander. Simmer until thoroughly heated. Serve in soup bowls; garnish with sieved hard cooked egg, if desired.