Heat the peanut or canola oil in a large sauté pan over medium heat. Once the pan is hot, add the cabbage, ginger, garlic, and scallions. Cook everything for about 2 minutes, stirring frequently. Add 1/4 teaspoon of kosher salt and stir. Turn off the heat and transfer the vegetables to a plate to cool for 10 minutes (see note 4).

Place the ground pork in a large bowl. Add the tapioca starch and water. Using chopsticks or a wooden spoon, stir the ingredients together for several minutes. After about a minute, you should hear squishing sounds and the meat should become more paste-like.
Add the soy sauce, sesame oil, 3/4 teaspoon kosher salt, and sugar to the bowl. Stir for about a minute to incorporate all the ingredients. Pour the vegetables into the bowl with the meat and stir together.

If you are using store-bought wrappers, fill a small bowl with water for wrapping and sealing the dumplings. If you are using fresh dumpling wrappers, cover the wrappers with a dry cloth or a layer of plastic wrap to keep them from drying out. Grab a baking sheet for the finished dumplings and a towel to cover the sealed dumplings to keep them from drying. Get a spoon for scooping the dumpling filling.

Heat a well-seasoned large cast iron skillet or large nonstick pan with 1 1/2 tablespoons of oil over medium-high heat. Arrange the dumplings over the pan. I usually cook about 15 to 17 dumplings at a time. Pan fry the dumplings for 2 to 3 minutes, until the bottoms are golden brown.