Wash oyster mushrooms and champignons, cut into slices, fry in a frying pan in oil for 3 minutes. on high heat. Then add the soy sauce and simmer on low heat under the lid until tender. Wash oyster mushrooms and champignons, cut into slices, fry in a frying pan in oil for 3 minutes. on high heat. Then add the soy sauce and simmer on low heat under the lid until tender.