Pan-fried chicken and Chinese cabbage jiaozi with black vinegar dipping sauce

Method

1. Thinly slice the Chinese cabbage into 2 mm strips, then roughly chop. Toss in a bowl with the 2 g salt and leave for 10 minutes to release its water. Meanwhile, crush the spring onion trimmings and 5 g sliced ginger with the flat of a knife, put in the 35 g lukewarm water and leave to infuse. Grate the remaining 10 g ginger and finely chop the spring onions. Squeeze the cabbage firmly in handfuls in a clean tea towel, without rinsing, as its salt seasons the filling. You should have about 120 g damp cabbage, with no more drops coming out.
2. Put the chicken mince, 20 g soya sauce, white wine, white pepper and grated ginger in the mixing bowl. Stir vigorously for 1 minute, always in the same direction. Strain the aromatic water, pressing the trimmings, then add in three batches, beating in the same direction after each addition until fully absorbed: the filling becomes sticky and glossy and holds in a ball on the spoon. Mix in the 15 g sunflower oil and 5 g sesame oil, then the cabbage and spring onions, stirring only enough to distribute them. Do not add more salt without checking: kosher chicken is already salted and the soya sauce supplies the rest.
3. Check the seasoning, as this is the only point when you can still adjust it: flatten a hazelnut-sized piece of filling and cook in the frying pan with a drop of oil for 1 minute on each side, then taste. It should be well seasoned, with ginger and pepper clearly present. If bland, add the reserved pinch of salt and beat for 10 seconds. Refrigerate the filling for 10 minutes: it firms up and is easier to enclose in the wrappers.
4. Set up the work surface: a small bowl with the 20 g sealing water, a tray dusted with 10 g cornflour, and the wrappers under a barely damp tea towel. Place a wrapper in your palm and put 1 heaped tbsp filling in the centre, 17–18 g and no more, as too much makes the seal split during steaming. Moisten half the rim with a fingertip. Fold into a half-moon, press the air out from bottom to top, then pinch the whole seam closed; make 3 or 4 small pleats along the front side if you wish. Stand each dumpling on its base, seam upwards, on the tray, leaving a finger's width between them. Shape all 28 dumplings, cover the tray with a barely damp tea towel and refrigerate. Cook within an hour or freeze on the tray, as described in the tips.
5. Make the dipping sauce: mix the remaining 15 g soya sauce, black vinegar, grated garlic, sugar and 3 g sesame oil until the sugar dissolves; divide between two small dipping bowls. For optional chilli oil, put the chilli flakes in a small heatproof bowl. Heat the 10 g sunflower oil in a small saucepan over a medium heat for 1 minute, until it shimmers, then pour over the flakes: they sizzle and the oil turns red. Serve separately. For the lacy skirt, divide the 240 g cooking water between two bowls, 120 g each, and mix 6 g cornflour into each.
6. Heat a 28 cm non-stick frying pan with half the cooking oil over a medium-high heat. Arrange 14 dumplings on their bases in a circular pattern, 1 cm apart, and fry for 2–3 minutes: lift one to check for a light golden base. Stir the cornflour water and pour around the edge of the pan, protecting yourself from splashes. Cover immediately and cook over a medium heat for 6–8 minutes, maintaining a gentle bubbling beneath the lid. As soon as the bubbling stops and you hear sizzling, uncover.
7. The tops should be plump and firm to the touch, and the wrappers glossy and translucent, with no floury patches. Let the bases crisp again in the dry pan over a medium-high heat for 1–2 minutes: the lacy skirt sets into a golden sheet and the base releases easily with a spatula. Cut one dumpling in half: the filling should be firm and white right to the centre, with clear juices. If not, add 2 tbsp water, cover for 2 minutes and let the pan dry again. Place a plate over the pan and invert the dumplings in one piece, with the golden skirt facing up.
8. Serve the first batch immediately, 7 dumplings each, with the dipping sauce: the bases stay crisp for only a few minutes, as is always the case with pan-fried dumplings. Wipe the pan with kitchen paper, as stuck-on starch would burn beneath the second batch. Cook the other 14 in the same way with the remaining oil and second bowl of cornflour water; they will arrive as the first plate is finished. With two 28 cm frying pans, cook both batches at once.