- 1 pound dried black turtle beans, picked over, soaked overnight in water to cover, and drained
- 1 ham bone or ham hock
- 6 cups chicken broth or water
- 3 tablespoons unsalted butter
- 2 medium-size yellow onions, chopped
- 2 cloves garlic, minced
- 1 cup chopped celery, including some leaves
- 1 teaspoon dried marjoram
- 1 bay leaf
- Salt to taste
- ¼ teaspoon freshly ground black pepper
- ½ cup dry sherry (optional)
- Combine the drained beans, ham bone or hock, and broth in the slow cooker. Cover and cook on HIGH until boiling, about 1 hour.
- Meanwhile, in a large skillet over medium heat, melt the butter. Add the onions, garlic, and celery and cook, stirring a few times, until softened, about 5 minutes. Add to the cooker along with the marjoram and bay leaf. Cover, turn the cooker to LOW, and cook the soup for 7 to 8 hours.
- Stir in the salt, pepper, and sherry, cover, and continue to cook on LOW 15 minutes longer.
- Discard the bay leaf and ham bone or hock, returning any bits of meat left on the bone to the soup. Puree in batches in a food processor or in the cooker with a handheld immersion blender. Taste to adjust the seasonings. Add some boiling water to thin, if desired. Ladle into soup bowls and serve hot.