Wash the napa cabbage and cut it into pieces; separate the crab sticks into strips; squeeze the water out of the shiitake mushroom slices and set aside.

Heat a little oil in a pan. Sauté the shiitake mushroom slices until fragrant, then add the cabbage and crab sticks. Stir-fry, add water, bring to a boil, then cover and simmer on medium-low heat.

Cook until the cabbage stems are softened, about 10 minutes. Add the umami stir-fry sauce, mix well, and serve.