2 tbsp. butter
1/4 c. onion, chopped
2 c. unpeeled cucumber, diced
1 c. watercress leaves
1/2 c. raw potato, finely diced
2 c. chicken broth
2 sprigs parsley
1/2 tsp. salt
1/4 tsp. ground pepper
1/4 tsp. dry mustard
1 c. heavy cream

Melt butter. Add onions and cook until transparent. Add other ingredients except cream. Bring to a boil and simmer 15 minutes or until potatoes are done. Puree in electric blender or meat grinder. Chill and before serving add cream.