Preheat your oven to 400°F (200°C). Arrange chicken backs, ginger slices, and green onions on a roasting pan. Roast for 30–40 minutes until golden brown. Transfer to a pot, submerge in water, and simmer for 2–3 hours. Cool, refrigerate overnight until congealed.

Combine all-purpose flour and salt in a mixing bowl. Gradually stir in hot water and then cold water. Mix to form shaggy dough. Knead for 8–10 minutes until smooth and elastic. Wrap and rest for 30 minutes.

Infuse grated ginger in 1 tablespoon of hot water. Mix ground pork, infused ginger, soy sauce, Shaoxing wine, and white pepper. Fold in 2 tablespoons of cooled jelly broth. Refrigerate for 30 minutes.

Divide rested dough into small portions, roll each into balls, and flatten into thin wrappers. Place 1 tablespoon of filling in the center, pinch edges to create pleats, leaving an opening at the top.

Prepare a steamer by boiling water. Line the basket to prevent sticking. Arrange dumplings in a single layer, cover, and steam for 8–10 minutes until wrappers are translucent.