Soak beans according to package directions. Rinse.
Add all ingredients except tomatoes to 3 quarts of water. Bring to boil, then reduce to low heat. Simmer for about two hours, until beans are soft and water is gone.
Add tomatoes. Cook until tomatoes are heated.
Add salt and pepper to taste. Garnish with fat-free sour cream and chopped green onions.
Yields 6 servings.