Cover black mushrooms with warm water; let stand 20 minutes.
Drain and rinse. Remove and discard stems from mushrooms. Cut mushrooms
into thin strips; reserve.
Heat peanut oil in 10-inch skillet
or wok until hot. Cook onions and gingerroot until tender; stir
in reserved black mushrooms and oyster mushrooms.
Mix eggs, wine
and soy sauce; pour into skillet. As mixture begins to set at bottom
and sides, gently lift cooked portions with spatula so that thin,
uncooked portion can flow to bottom. Avoid constant stirring. Cook
until eggs are thickened throughout but still moist, 3 to 5 minutes.