Place the beans in a large sauce pan along with the remaining soup ingredients. Bring to a boil, reduce heat and simmer, covered, about 1 1/2 to 2 hours or until the beans are tender, stirring occasionally. Lightly mash some of the beans with a potato masher or blend in a blender, if desired. Continue to cook, uncovered, until soup reaches desired consistency. Ladle soup into warmed bowls; top with sour cream, onions and coriander.
Per Serving: 373 Calories (16.3% from fat); 7g Fat (4g Sat, 2g Mono, 1g Poly); 36g Protein; 46g Carbohydrate; 9g Dietary Fiber; 13mg Cholesterol; 1277mg Sodium. Food Exchanges: 2 Grain (Starch); 3 Lean Meat; 1 1/2 Vegetable; 1 Fat.