Drain canned beans, or rest dry beans in cold water for 6 - 8 hours.
Dice and saute bacon or salt pork, rendering it entirely over low heat.
Dice garlic, onions, and celery stalks, and saute in rendered fat until soft.
Add in tomato paste and stir quickly until heated through and combined with vegetables.
Add in black beans, chicken stock and 7 cups water.
Drop in pork or ham hock(s) and oregano.
Bring to boil, then reduce heat and simmer uncovered for 2 hours.
Remove hock(s), recover any meat possible and add into soup, discard bones, etc.
For traditional soup, serve with diced raw onions, vinegar, and olive oil as garnishes, over white rice. Less traditional, add sour cream, hot sauce, cilantro, or what have you!