Heat 2 tb margarine in a soup pot. Add onions & saute over moderate heat till golden. Add next 5 ingredients & bring to a boil. Add seasonings & wine; cover & simmer over moderate heat for 15 minutes.
Add half the sliced white mushrooms & simer 10 minutes. Remove soup from heat & let stand for a few minutes.
Wipe shiitake, remove & discard stems, slice caps. Heat remaining margarine in skillet, saute remaining white mushrooms & shiitakes,covered, for 10 minutes.
Add beans to soup & puree in batches. Return to soup pot & stir in the sauteed mushrooms. Grind in pepper. Before serving, simmer for 10 minutes. Adjust consistency if too thick. Sprinkle each serving with minced parsley.
Nava Atlas, "Vegetarian Celebrations"