Cover the dry beans with water in a large pot. Do not salt the water. Bring to a boil. Reduce heat to medium-low, cover and cook until tender, about 1 hour.
Rinse the rice with cold water until the water runs clear.
Use a large, 8-quart covered stockpot. Heat the olive oil and saute the onion and green pepper until tender. Add the garlic and sofrito and saute another 1 to 2 minutes. Add the tomato paste, black beans, oregano, cumin and bay leaf. Cook for about 5 minutes, stirring gently.
Add the chicken stock and the rinsed rice. Season with plenty of salt. Bring to a boil, reduce heat to low, cover and cook for about 20 to 30 minutes, or until rice is fully cooked.