Cover the shitake mushrooms with boiling water and soak for 20-30 minutes. Squeeze out the excess liquid from the mushrooms. Remove and discard the stems. Cut caps into thin slices. Reserve 1/4 cup of the soaking liquid.
Heat the vegetable and sesame oil in a saucepan over medium heat and add the ginger, shitake , enoki and button mushrooms and cook for 3 minutes while stirring. Add the bamboo shoots , stock , soy sauce , and reserved mushroom soaking liquid. Bring to a boil and simmer for 5 minutes.
Combine cornflour with 2 tablespoons water in a small bowl. Add the black and white peppers, and black and white vinegars to the soup and cook till it simmers. Stir in the cornflour mixture and boil until mixture thickens slightly. Serve.