In a stand mixer, mix the flour, salt and boiling water until you have a rough ball shape. Dust your work surface with flour. Remove from the bowl and knead for 10 minutes until smooth. Divide the dough into two and rest for 20 minutes.
Divide each piece of rested dough into 16 even-sized pieces. Roll each piece of dough into a small ball and then flatten it. Dust your working surface again. Take one piece of dough and press it to a round disc. Rotate the wrapper when moving your rolling pin. Repeat the process, rotate the wrapper-roll and rotate the wrapper-roll. The wrappers will have thicker center and thinner edges naturally.
Make the filling; In a large skillet over medium high heat, add 3 tablespoons oil and add the ginger and onions. Cook until fragrant and onions until translucent. Add the chopped mushrooms and stir-fry for another 3-5 minutes, until the mushrooms are tender and any liquid released by the mushrooms has cooked off.
Add the cabbage, carrots, and stir-fry for another 2 minutes, until the veggies are tender and all the liquid released has been cooked off. Transfer the vegetable mixture to a large mixing bowl and allow to cool. Then add the cilantro, chives, white pepper, sesame oil, shaoxing wine, soy sauce, salt, sugar and mix well.
To assemble the dumplings; Place a heaped teaspoon of filling into the centre of each wrapper. Fold over into a half moon shape. Cradle the wrapper in one hand and use the other hand to create pleats along the edge furthest away from you, pinching the two edges together after each pleat as you go, to create a crescent shape. Avoid getting any filling on the edges and be sure to pinch firmly as you pleat to create a good seal.
Cook the dumplings in two batches. Heat the oil in a large frying pan over medium heat. Fry the dumplings flat side down for about 2 minutes until a golden crust forms on the bottom. Add the 1/4 cup water and immediately cover with a lid and let the steam cook the dumplings for 8 minutes or until all the water has evaporated. Remove the lid and let the dumplings to cook for a further minute until they lift off from the bottom of the pan easily. You might need a spatula to help them along if they are a little sticky, being careful not to break the wrapper. Repeat with the second batch.
Serve the dumplings in a big plate. Drizzle the spicy sauce on top, or serve on the side for dipping. Enjoy.