1Melt butter in pan, do not brown. Add vegetables, toss to coat with butter, then press parchment paper on top of vegetables--this is called "sweating"-- for better flavor. Put lid on pan and simmer very gently until vegetables have softened. Do not brown.
2Remove paper, add chicken stock, bring to a boil, then simmer until vegetables are soft.
3Put in blender and puree until smooth. Pour back in pan, add salt, pepper, and cream. Simmer gently, do not boil or cream will curdle, until heated through.