1 pound dried black beans, soaked (see Kitchen Notes for fast and slow soaking methods)
1 smoked ham hock, 3/4 to 1 pound
8 cups water
2 bay leaves
1 medium yellow onion, chopped
1 red bell pepper, chopped
1 large jalapeño pepper, finely chopped (see Kitchen Notes)
2 carrots, peeled and diced
2 ribs celery, peeled and diced
2 large cloves garlic, minced
1 tablespoon ground cumin
1 15-ounce can diced tomatoes, drained
freshly ground black pepper
2 tablespoons fresh lime juice (see Kitchen Notes)
sour cream (optional)
chopped cilantro for garnish
Place soaked beans and ham hock in large, heavy stock pot or Dutch oven. Add water and bay leaves and bring to a boil. Reduce heat and simmer, covered, for 1-1/2 hours.
Meanwhile, heat 2 tablespoons oil in a large sauté pan or skillet. Add onion, bell pepper, jalapeño pepper, carrots, and celery. Toss to coat with oil and sweat vegetables for four or five minutes, stirring frequently. Clear a space in center of pan, drizzling in extra oil if needed, and add garlic and cumin. Cook until fragrant, about 45 seconds, stirring constantly. Remove pan from heat and toss vegetables to combine. Set aside.
Using tongs, transfer ham hock to shallow bowl and set aside. Remove and discard bay leaves; add vegetable mixture and tomatoes to pot. Season generously with fresh ground black pepper, but don’t add any salt at this point. Transfer four cups of soup to food processor and carefully purée (do this in two batches, if necessary). Return to pot.
Bring to a boil, reduce heat and simmer, uncovered, for 30 minutes or more. Meanwhile, when ham hock has cooled enough to handle, remove the skin, fat and bones and chop the meat into small pieces. Return to pot. As the soup simmers, you may get a bit of foam on the top. If so, skim it off and discard. This happened late in the cooking process for me.