3 tablespoons olive oil
1 small yellow onion, chopped (1/2 cup)
2 garlic cloves, minced
1 teaspoon ground cumin
1 large stalk celery, chopped (3/4 cup)
1 large carrot, chopped (3/4 cup)
4 cups chicken or vegetable stock
3 15 1/2-ounce cans black beans, rinsed and drained
Juice from 1 lime
1 tablespoon tomato paste
Salt
Sour cream, salsa, and cilantro (for serving)

In a large stockpot, heat the oil, onion, and garlic and cook until the vegetables are tender. Stir in the cumin and cook 1 minute. Add the celery, carrot, stock, and beans. Heat to boiling. Reduce heat to low, cover, and simmer 15 to 20 minutes. Stir in the lime juice and tomato paste. To thicken soup, puree the beans in a blender or food processor and return to pot. Taste and add salt if necessary. Serve with sour cream, salsa, and cilantro.