Makes 6 servings at 67o each.
1. Halve, peel and seed squash. Cut into 1-inch pieces. Place in saucepan along with onion and carrots. Add chicken broth and salt. Simmer, uncovered, 40 minutes.
2. Puree soup in blender or food processor along with butter. Pour a little hot puree into heavy cream; add to soup. Serve with a dollop of sour cream, if desired.