Black Bean Soup

8 cups chicken or vegetable stock
2 teaspoons olive oil
1 onion, chopped
1 cup carrots, chopped
1 cup celery, chopped
2 cloves garlic, minced
2 teaspoons dried oregano
1 teaspoon dried thyme
1 bay leaf
1/2 teaspoon cayenne pepper
3 tablespoons fresh lime juice
Fresh cilantro (optional)

Rinse and sort though black beans, discarding any that are shriveled
or discolored. Place beans in a large stockpot. Cover beans with
water and refrigerate to soak overnight. Drain beans and return to
stockpot. Add stock and heat to boiling.

Meanwhle, heat olive oil over medium-high heat in a large skillet.
Add onion, carrot, celery and garlic and saute until tender,
approximately 5 minutes. Add to stockpot along with oregano, thyme,
bay leaf and cayenne pepper. Cover stockpot and reduce heat to simmer
for 3 to 4 hours.

Transfer soup to blender or food processor and puree to desired
thickness. Just before serving add lime juice and garnish with a
sprig of fresh cilantro, if desired. Add salt and pepper to taste
and serve.