Cuban Black Bean Soup with Chorizo Sofrito

1. For soup: In soup pot, combine black beans and enough cold water to cover by 1 inch. Bring to boil over high heat; cook 1 minute. Remove from heat and cover. Let stand 1 hour. Do not drain beans.
2. Add onion, bell pepper, garlic, cumin, oregano, bay leaves and 1 teaspoon salt to pot. Pour additional water into pot to cover ingredients by 1 inch. Bring to boil over high heat. Reduce heat to low and simmer, adding hot water as needed to keep beans well covered, until they are tender, about 2 hours. Discard bay leaves.
3. Into blender, transfer beans and vegetable chunks with about 2 cups of cooking liquid. Puree mixture with blender lid ajar to allow steam to escape. Stir puree back into pot. Adjust soup consistency with more puree or water, as needed. Stir in cider vinegar and season to taste with salt and pepper. Keep soup hot.
4. Meanwhile, prepare sofrito: In large skillet over medium heat, heat 1 tablespoon oil. Add chorizo and cook, stirring often, until browned, about 5 minutes. Using slotted spoon, transfer chorizo to paper towels to drain.
5. Add remaining 2 tablespoons oil to skillet and heat over medium heat. Add onion, bell pepper, chilies, garlic, cumin, oregano and salt. Cook, stirring often, until sofrito is tender but not browned, about 15 minutes. Remove from heat and stir in cilantro. Stir reserved chorizo into sofrito.
6. Stir about half of sofrito into soup.
7. To serve, ladle soup into bowls and garnish each serving with spoonful of remaining sofrito.