Pour water into the bottom part of the steamer.

Thinly slice the king oyster mushrooms and place them in the steamer basket.

Add the beef brisket on top of the mushrooms.

While waiting for the food to steam, combine all the sauce ingredients in a small bowl.

Place the steamer on the stove, cover it, and steam for 8 minutes after the water starts boiling.

After 8 minutes, transfer the steamed mushrooms and beef brisket to a serving plate.

Garnish with chopped chives.

Pour the prepared sauce over the dish and mix well before serving.