1. Combine first 7 ingredients with 2 cups water in a large Dutch oven, and bring to a boil over high heat. Adjust heat so liquid barely bubbles, and simmer, partially covered, 30 minutes. Remove meats. Add leek, 2 cans beets with liquid, and next 6 ingredients; simmer, uncovered, 30 minutes. Puree remaining can of beets with its liquid in a food processor.
2. Return boiled meats to Dutch oven, and simmer, uncovered, 20 minutes. Stir in pureed beets and parsley, remove from heat, and let stand 10 minutes. Add more salt, if desired. Discard bay leaves.
3. Ladle into warm soup bowls, top each portion with sour cream, and garnish, if desired.