Peel the onion, clean carrots ... peeled, thinly sliced potato. After 3 more minutes, ... in blender with parsley, then reheat; adding extra seasonings as required.
Melt butter in heavy medium saucepan; add parsley, stirring until wilted, 3 minutes. Add broth, grated potato and chervil; increase heat. Bring ... parsley sprig and serve.