This is a great soup – zesty, flavorful, and not too “beany.” Because it is prepared with canned beans, it is very quickly made. Serve it with sourdough bread for a hearty lunch or supper.
In a medium-size saucepan, heat the oil over medium heat. Add the onion and garlic and saute for 5 minutes, until the onion is tender.
In a blender or food processor, combine the tomatoes with liquid and three-quarters of the beans. Process until smooth. Add to the sauteed onion along with the re-maining black beans, broth, and cumin. Cook over low heat for about 15 minutes, stirring occasionally.
Serve the soup hot, topping each bowl with a sprinkling of scallions and chopped tomatoes and a dollop of sour cream.