Soak the black moss in water, rinse carefully to remove dirt and sand.
Place cabbage leaves in a saucepan with 1 cup of water and 1 tbsp oil. Cover and cook over low-heat. When steam appears, turn off the heat. Allow to stand for 2 mins. Drain and retain the cabbage stock.
With 2 tbsp oil, stir fry the shredded ingredients A and black moss. Add the seasoning and give it a quick stir. Remove and cool.
Place a tbsp of cooked vegetables on each cabbage leaf and wrap tightly. Arrange on a platter of rack and steam for 10 mins. Remove and arrange on a plate. Do not discard the balance gravy.
Combine the cabbage stock and gravy. Thicken with cornstarch. Pour over the cabbage parcels. Serve hot with rice.