Cut the cabbage and king oyster mushrooms into bite-sized pieces.
Thinly slice the onion and carrot as well.
Heat cooking oil in a pan over medium heat, then stir-fry the onion and carrot first.
Add the king oyster mushrooms and cabbage, and stir-fry together.
Season with salt and pepper.
Once the vegetables have softened, turn off the heat and transfer to a plate.