Start by heating a small amount of grapeseed or vegetable oil in a skillet over medium heat.
Add the finely chopped cabbage and scallions, cooking them just until they soften, then transfer to a bowl to cool.
In the same mixing bowl, combine ground pork with minced ginger, minced garlic, cooled cabbage mixture, salt, and pepper.
Sprinkle the potato starch over the meat mixture, add water, and stir thoroughly to bind the filling.
Pour in the dry sherry or Shaoxing wine, soy sauce, sesame oil, and sugar; mix until all ingredients are well integrated.
Lay out the round dumpling wrappers and place a small spoonful of filling in the center of each wrapper.
Moisten the wrapper edges with a bit of water and carefully fold them over, pressing the edges to seal the potstickers tightly.
Heat a non-stick skillet with a light coating of oil over medium-high heat.
Arrange the potstickers in the skillet in a single layer and cook until the bottoms are golden brown, about 2 to 3 minutes.
Pour enough water into the skillet to cover about one-third of the potstickers’ height, then cover tightly to steam for 6 to 8 minutes until the filling is cooked through.
Remove the lid and continue cooking to evaporate any remaining water and crisp up the bottoms again, about 2 more minutes.
Serve the potstickers hot with a dipping sauce made from reduced-sodium soy sauce mixed with white vinegar to taste.