Wilt cabbage 20 min, squeeze. Soak mushrooms 30 min, squeeze, finely chop. Mix with remaining Filling ingredients. Wrap. Pan fry 2 min, ¼ cup water, pan-steam 5 min.
Prepare cabbage - Toss cabbage with ½ tsp salt in a bowl. Set aside for 20 minutes. Then grab handfuls and squeeze out excess water as best you can. Place squeezed cabbage in a bowl for mixing the filling in.
Shiitake mushrooms - Soak mushrooms in 1 litre of boiling water for 30 minutes. Squeeze out excess liquid and finely chop into 2 mm pieces. Add to the filling bowl.
Potato - Add grated potatoes to filling mix, including all the liquid that leached out when you grated it. We want all that starchy juice for its binding power!
Filling - Add remaining ingredients into the filling bowl, mix to combine. It will look crumbly - don't worry, everything sticks together better when steamed thanks to the potato.
Dumpling wrappers - Take one wrapper from the packet. Keep unused wrappers covered so they don't dry out.
Wrap dumplings - (See video at 1m 30s!) Place a wrapper in your non-dominant hand. Dip your index finger in water and run it along the lower half of the wrapper (edge closest to you). Place 1 loosely-packed tablespoon of filling in the centre. Fold the wrapping over the filling, then seal with pleats. (If this is too hard, skip the pleats and seal flat).
Finished dumplings - Stand dumpling upright with the pleats on top, and lightly press down to flatten the base. Shape gently into a slight curve. Place on a tray lightly dusted with cornflour/cornstarch. Repeat for remaining dumplings. Keep completed dumplings covered with a tea towel to prevent them from drying out. If you're making ahead, cover dumplings with cling wrap and refrigerate. See storage notes.
Cooking vessel: Use a large non-stick pan with a lid (Note 6).
Pan fry: Heat 1 tablespoon oil over medium high heat. Pan fry 12 to 15 dumplings for 2 minutes until the base is golden brown.
Steam: Pour over ¼ cup water over the dumplings in the skillet - it will steam and bubbly vigorously! Place the lid on and steam for 5 minutes or until the water in the pan has evaporated.
Cooked! Remove the lid. The water should have been driven off, and the wrapping should be semi-transparent (indicating it is cooked). The base should be crispy again. If not, leave the pan uncovered for a bit until the base crisps up again in the oil.
Serve: Scoop the dumplings up with a spatula and place on a serving plate. Serve with soy sauce and chili paste for dipping, or rice vinegar mixed with soy sauce. Best served fresh - I get another batch cooking as we eat the freshly cooked ones!
Using either a bamboo steamer set over a large wok with simmering water, or other larger steamer. Line with a fitted sheet of parchment paper with holes, and steam the dumplings for 8 minutes.
