8 oz. dried black beans, rinsed and soaked overnight
1 small bay leaf
1/3 tsp. dried thyme
1 small parsley sprig
- Drain the black beans.
- In a pot, combine them with enough water to cover by 3 inches.
- Place the bay leaf, parsley and thyme in a piece of cheesecloth and secure with a string to make a satchel
- Add the herb satchel, quartered onion and salt tp the beans; Bring to a boil over medium-high heat.
- Reduce the heat to low, cover and cook until the beans are just tender, about 1 hour.
- Drain the beans and discard the herb satchel and onion; Wipe out the pot.
- In the same pot, heat the olive oil; Add the chorizo and cook over moderate heat, stirring occasionally, until starting to crisp, about 4 minutes.
- Add the chopped onions, the garlic and cumin; season with salt and pepper, to taste.
- Cook over moderate heat, stirring occasionally, until the onions are tender, about 10 minutes.
- Add the stock and 1 cup of water and bring to a boil.
- Return the beans to the pot, cover, reduce the heat to low and continue cooking until the beans are very tender and the soup has thickened, about 1 hour and 45 minutes. You may need to add up to another cup of broth or water towards the end of cooking it it thickens faster than the beans cook.
- Ladle the soup into bowls and serve garnished with radishes and cilantro, if using.
- Pass lime wedges and tortilla chips at the table.