Blanch cabbage leaves in boiling water until they begin to wilt (it should take no more than 20 seconds). Drain and set aside.
Use a vegetable peeler to peel off 8 narrow strips of carrots. Blanch for a few seconds then drain (carrot is purely for an aesthetic reason so it’s optional).
Mix the filling
Squeeze out excess water in shiitakes mushrooms (keep the water in which the mushrooms are soaked for later use). Chop them into tiny pieces.
Put mushrooms, minced meat and all the seasonings into a bowl. Mix well.
Assemble the rolls
Place ⅛ of the filling in the middle of a cabbage leaf. Wrap it into a cylinder shape.
Tie the roll with a strip of carrot (please refer to my tutorial video below). Repeat to finish the rest.
Steam the rolls
Place the rolls into a serving plate then put into a steamer. Steam for 10 minutes.
If you don’t have a steamer, see note 3 for an alternative solution which is also demonstrated in my tutorial video below.
Make the sauce
While waiting for the rolled to cook, mix 3 tablespoons of the mushroom water with oyster sauce and cornstarch. Stir well.
Heat up the sauce over high heat. Remove as soon as it thickens. Pour it over the rolls. Serve warm.
Make in advance
You may keep raw, wrapped cabbage rolls in the fridge for up to 24 hours. Extend the steaming time to 12 minutes if just taken out from the fridge.
Video
Notes
1. I use savoy cabbage for this dish. The leafy part of Napa cabbage (aka Chinese cabbage) works very well too.2. The water in which the shiitake mushrooms are soaked is very aromatic so it adds great umami taste to the sauce. You may also use stock if you wish.3. How to steam without a steamer? Put a small bowl in the middle of a large pot/wok. Fill the pot/wok with water (not over the bowl). Then place the serving plate on top of the bowl. Steam the usual way (Please refer to the video above).