In a medium bowl, combine the pork, scallions, ginger and garlic. In a small bowl, whisk the stock, soy sauce, sherry, vegetable oil, sesame oil, 1/8 tsp. pepper and a rounded 1/4 tsp. salt.
Pour the stock mixture over the pork mixture. Mix until well incorporated, stirring quickly at the end to create a thick, smooth mixture. Cover and let stand at room temperature 30 minutes to allow the flavors to meld.
Line a rimmed baking sheet with parchment and dust with flour. Place 1 wrapper on a work surface; brush the edges lightly with water. Place the wrapper in the palm of your hand, cupping it slightly in the center. Scoop about 2 tsp. of the filling into the center of the wrapper, leaving a 1/2-inch border. Fold the wrapper in half, enclosing the filling. Press the edges firmly to seal.
Pleat the dumpling's sealed edge by folding every 1/4 inch, forming 4 to 5 pleats; press firmly to seal. Transfer the dumpling to the prepared baking sheet; cover with a kitchen towel. Repeat with the remaining wrappers and filling, spacing the dumplings 1/2 inch apart on the baking sheet.
In a large nonstick skillet with a lid, heat 2 tbsp. oil over medium-high. Working in batches, add the dumplings, one at a time and seam-side up, to the skillet. Fry until golden, 1 to 2 minutes.
Holding the lid between you and the skillet in order to protect yourself from splatters, add 1/3 cup water, then cover the skillet immediately. Reduce the heat to medium; cook 3 minutes. Adjust the lid so it's slightly ajar (this allows steam to escape). Cook until most of the water evaporates and the dumplings begin to sizzle, 1 to 2 minutes.
Uncover and cook until the dumplings are browned and crispy on the bottom, 2 to 4 minutes. Remove from the heat. When the dumplings stop sizzling, transfer them to a plate. Serve with the dipping sauce.
