In a large saucepan combine broth, carrots, onion, bay leaf, pepper, and, if desired, cloves. Bring to boiling; reduce heat. Simmer, covered, for 15 to 20 minutes or until carrots are tender. Remove bay leaf. Cool slightly.
In a blender container or food processor bowl place carrot mixture, half at a time. Cover and blend or process until smooth. Return mixture to the saucepan. Stir in water. Bring just to boiling. Stir a small amount of liquid into sour cream. Return to saucepan along with the rice. Heat through but do not boil. Sprinkle with parsley. Makes 6 side-dish servings.