Shanghai Pan-Fried Pork Soup Buns

Cut the chilled aspic into small 1/4-inch cubes and gently fold it into the pork filling until evenly distributed. Refrigerate the filling for at least 1 hour, or until very cold.

Make the dough 1 1/2 to 2 hours before serving. In the bowl of a stand mixer fitted with a dough hook, combine the cake flour, all-purpose flour, salt, and instant yeast. Add the water slowly with the mixer on low, then knead for 10 minutes until the dough is smooth, soft, and holds its shape.

Shape the dough into a ball, lightly oil the surface, cover, and let it proof at room temperature for 30 minutes.

Lightly oil a wide nonstick skillet or a well-seasoned pan. Once the dough has proofed, knead it again briefly until smooth. Work with one-third of the dough at a time and keep the rest covered so it does not dry out.

Roll the dough into a log and divide it into 20 g pieces. Roll each piece into a ball, flatten it, and roll it into a 4-inch round wrapper with slightly thinner edges and a thicker center.

Place about 2 tbsp of filling in the center of each wrapper. Pleat and seal the top carefully, keeping your fingers as dry and clean as possible so the dough seals well.

Set the shaped buns in the oiled pan as you work, leaving about 1/2 inch of space between them. Traditionally they are cooked pleat-side down, but pleat-side up is easier if you are worried about leaks.

Place the pan over medium heat and add enough neutral oil to coat the bottom generously. Let the buns fry undisturbed for 8 to 10 minutes, until the oil bubbles steadily and the bottoms begin to turn light golden.

Pour in enough water to come about one-third of the way up the buns. Cover immediately and cook over medium-low heat for 8 to 10 minutes. Uncover, sprinkle with toasted sesame seeds and extra scallions if desired, then cover again and cook about 5 minutes more, until the water has evaporated and the bottoms are deep golden brown. Remove gently and serve right away with Shanghai rice vinegar or black vinegar.