Place shiitake mushroom in a bowl and pour (1 cup) hot water to cover to reconstitute it. Once hydrated and cold enough to handle, squeeze out the liquid and reserve the liquid and chop into small pieces.
4 pcs dried shiitake mushrooms
In a pot with boiling water, blanch the spring onion leaves until softened (to be used as tie).
3 stalks spring onion
Remove the core of the cabbage. Blanch cabbage leaves in boiling water until they begin to wilt (it should take no more than 20 seconds). Separate the leaves. Drain and allow to cool to touch.
1 head round cabbage or napa cabbage
Trim the rib (thick white part) of the leaves to become more pliable. Reserve the trimmings and chop them finely.
In a bowl, combine ground pork, mushroom, carrots, green onion, chopped cabbage trimmings, soy sauce, oyster sauce, salt, and pepper. Mix until well combined.
500 grams ground meat, 4 pcs dried shiitake mushrooms, 1 small carrot, 1 tablespoon light soy sauce, 1 tablespoon oyster sauce, ½ teaspoon salt, ⅛ teaspoon ground pepper
Place a cabbage leaf flat on a plate, scoop about 2 spoonful of the filling and place it on top of one end of the cabbage leaf then wrap the sides over it and roll. Tie the roll with a green onion leaf if needed.
Place the rolls on a plate, seam side down. Place the plate on a steamer and steam for 12-15 minutes. Remove the plate from the steamer and transfer the rolls into a serving plate. Do not throw the liquids from the cabbage on the plate.
For the sauce, combine the water from soaking the mushroom and cornstarch to make a slurry. Collect the liquids from the steamed cabbage in a saucepan and season with oyster sauce and sesame oil. Bring to a gentle simmer over low heat and once simmering add the slurry and cook until it the sauce thickens.
2 teaspoons cornstarch, liquid from mushroom soak, liquid from steamed cabbage, 1 tablespoon oyster sauce, 1 teaspoon sesame oil
Pour the sauce over the cabbage rolls and serve.