Place chicken bones and feet in a small stockpot or large saucepan and add cold water to cover. Bring to a boil; drain and rinse with cold water. Return chicken to the saucepan and add spring onions, ginger, wine, and about 2L of cold water.

Bring to a boil, skim surface of any foam, and reduce heat. Simmer, skimming often, until liquid is almost opaque and reduced to 500 ml, 3 hours. Season with salt, and strain into a 13x9” baking dish; discard solids. Chill until set, at least 2 hours and up to 3 days. If making ahead, cover soup with plastic wrap once jelled.

Put the stock, wine, meat, green onion, and ginger in a small saucepan. Bring to a boil and cook, uncovered, for about eight minutes, or until the stock has reduced by half. You should end up with around 250ml. Strain the soup, discard the solids, and set aside to cool and concentrate for 15 minutes.

Return the stock to the saucepan and sprinkle in the gelatin. Heat over medium-high heat, stirring the soup until the gelatin dissolves. Bring the stock to a simmer and then turn off the heat. Pour it into an 8 in by 8 in (20 cm by 20 cm) baking pan to make a thin layer that will cool quickly and be easy to cut up.

Mix ground meat, spring onions, garlic, soy sauce, salt, wine, sugar, oil, ginger, and pepper with chopsticks in a medium bowl, stirring in one direction until it all comes together and a light film forms on the sides of bowl, about 20 seconds. Cut a fine crosshatch pattern in jelled soup to create very small pieces (about 3mm squares). Scrape into bowl with filling and mix to combine. Cover and chill until ready to use.

While boiling water for the dough, combine the two flours in a mixing bowl. Combine the just-boiled water and the oil in a separate bowl.

While mixing with chopsticks, add the water-and-oil mixture to the flour. The result will be a soft, warm dough. If the dough is too dry, add water by the half-teaspoon to soften. Gather the dough into a ball and transfer it to a very lightly floured work surface. Knead it for about five minutes.

When you’re done kneading, the dough should be smooth and a little bit elastic. Test it by pressing a finger into the dough. It should bounce back moderately quickly and leave a shallow indentation. Place the dough in a ziplock-style bag and seal it well, pushing out all of the excess air as you close the bag. Let the dough rest at room temperature for an hour before using. You can refrigerate the dough overnight as long as you bring it back to room temperature before moving forward.

Divide dough into 4 equal pieces. Working with 1 piece at a time and keeping other pieces covered with plastic wrap, roll out dough with your palms to make 12 inch-long ropes.

Cut each rope into twelve 1 inch-pieces with bench scraper. Using a ruler as a guide means all your pieces will be the same size, resulting in uniform dumplings.

Working with 1 piece of dough at a time and keeping other pieces covered in plastic wrap, roll until round, and then press down with your palm to make a disc.

Use dowel to roll out into thin rounds—work from the center moving outward, applying slightly more pressure as you reach the edges to make them a little thinner. Cover with plastic.

Mix spring onion, ginger, vinegar, and soy sauce in a small bowl; set aside.

Lay a wrapper across the upper part of your palm and bottom half of the fingers of your nondominant hand. Spoon 1 tbsp filling into wrapper, making sure to get some pieces of jelled soup. Spoon a couple more pieces of jelled soup into center of filling.

Slightly cup your palm around dumpling and gently grasp edge of wrapper between your thumb and index finger. Position your other thumb and index finger half an inch away in the same fashion. Using fingertips on one hand, gently pull and stretch wrapper outward before bringing it in to meet opposite fingers. Carefully fold stretched area in on itself, creating a pleat. Pinch to seal. Rotating dumpling as you work, repeat process to create a series of 18 pleats, leaving a small hole in the center. Cradle dumpling in your palm, gently rotating it and working filling upward so dumpling is shaped like a fig. This step elongates the dumpling, eliminating air between wrapper and filling. Pinch edges together and gently twist to seal.

Place dumpling in lightly greased baking tray and cover with plastic wrap. Repeat with remaining wrappers and filling.

Place dumplings in a steamer over a large saucepan of rapidly boiling water, making sure water doesn’t touch steamer, and cover. Steam dumplings 8 minutes (10 if frozen). Serve directly from steamer with dipping sauce.