In a saucepan, saute the carrot, onion, and celery in the butter until soft, about 8 to 10 minutes. Add the flour and cook for 5 minutes, stirring often.
Add the broth gradually, stirring until slightly thickened and smooth. Add the bay leaf, simmer uncovered for 30 minutes, then remove the leaf.
Add the remaining ingredients and simmer for about 5 minutes.
