Melt butter in large saucepan over medium heat Add mushrooms and cook for 3 minutes. Add onions and celery and cook, stirring, until liquid evaporates. Add potatoes and water, bring to boiling, reduce heat and simmer covered for 20 minutes. Remove from heat, allow to rest 5 minutes. Stir in sour cream, minced green onion and parsley. Pour into soup bowls. Garnish with chopped dill. Do not boil after sour cream has been added, or soup will curdle. Makes 11 cups. Author says that this soup was served at a Sternwheeler fund raising event and was raved about. Source: The Columbia River Cookbook, by Joan Van Divort (1981), Columbia River Press, ISBN# 0-939688-04-2 I believe this soup was also served at authors restaurant, The Columbia River Kitchen, Wenatchee, Washington (in the late 1970s). MC formatted by Brenda Adams ; mc post 6/17/97 Recipe by: The Columbia River Cookbook, by Joan Van Divort (1981) Posted to MC-Recipe Digest V1 #648 by Badams on Jun 22, 1997