Cut the halved cabbage crosswise into very thin strips, then chop the strips a few times so they are in shorter pieces. You should have about 4 cups. Place the sliced cabbage in a medium bowl and toss with the kosher salt. Let stand for 10 minutes (the cabbage will release some liquid).

Grab the cabbage by handfuls and give them a good squeeze to remove as much liquid as possible (it won't be a massive amount, but this is an important step). Transfer the squeezed cabbage to a large, dry mixing bowl.

Add the pork, vinegar, ginger, green onions, garlic, and soy sauce. With your hands, mix gently until the ingredients are evenly combined.

Set up your dumpling making station: Line up your dumpling package, a small bowl of water, the pork filling, a parchment-lined baking sheet, and whatever work surface you'd like to use for shaping the dumplings. Set 3 wrappers in front of you.

For each dumpling, place a loose 1 tablespoon of filling in the center. Dip your finger in the bowl of water and run it all around the edges of the wrapper to create a seal.

Lift one edge of the dumpling wrapper to fold it in half (if your wrappers are a square, fold two opposite sides together to close it like a book). Gently press the edges to seal it. With your fingers, make small pleats along the edges of the dumplings, wetting your fingers as needed so the pleats stay. This will take some practice — have fun with it! I end up with 5 - 6 pleats per dumpling.

Transfer to the parchment-lined baking sheet. Repeat with the remaining wrappers and filling (you'll get the hang of it more and more as you go). At this point, you can cook the dumplings immediately or freeze them for later.

When ready to cook: fill a measuring cup with a spout with water, then set it and a tablespoon measure near your stove. Grab a large skillet with a lid that fits over it. Heat the skillet over over high heat. Drizzle in a few teaspoons of oil and swirl so that the pan has a thin but complete coating.

Once the oil is hot, quickly place dumplings in the skillet in a single layer so that the dumplings are close together but their sides do not touch.

Cook on the first side until the bottoms are golden brown and seared, about 3 minutes. Quickly add 3 tablespoons of water to the pan (be careful, it will spatter!). Immediately cover the skillet and reduce the heat to low. Let cook until the wrappers look semi-translucent and the filling is cooked through, about 4 to 5 minutes for fresh or 6 to 8 minutes if the dumplings were frozen (cut one open to check).

Transfer the dumplings to a serving plate. Enjoy immediately dipped with additional soy sauce if desired. Repeat with remaining dumplings, or freeze them for later.