How to Make It
Place rice in a fine wire-mesh strainer, and rinse thoroughly under cold water. Drain and set aside.
Rinse and sort beans according to package directions. Bring beans, water, ham hock, oregano sprigs, bay leaves, and jalapeño to a boil in a stockpot or large Dutch oven over high. Reduce heat to medium-low; cover and simmer until beans are tender, about 45 minutes.
Place a colander inside a large bowl. Carefully pour bean mixture into colander, reserving black bean cooking liquid in bowl. Discard jalapeño halves, bay leaves, and oregano sprigs. Remove ham hock; chop meat, and set aside with black beans.
Heat oil in a large saucepan over medium-high. Add onion and bell pepper, and cook, stirring often, until tender, about 5 minutes. Add garlic, and cook, stirring constantly, 30 seconds. Stir in tomato paste, cumin, and fennel, and cook, stirring often, until tomato paste is slightly caramelized, about 3 minutes. Add rice, and cook, stirring constantly, 1 minute.
Stir ham meat, black beans, salt, pepper, and 4 cups reserved black bean cooking liquid into rice mixture, and bring to a boil over high. Reduce to medium-low; cover and simmer until rice is tender, about 20 minutes. Fluff mixture with a fork, and serve immediately with sour cream and chopped cilantro.