Sauté the cabbage with 1 Tbsp canola or vegetable oil in a large skillet over medium heat until wilted to half its volume. Transfer the cabbage to a large bowl.

Slice the green onions, mince the garlic, and grate or chop the ginger. Add the onions, garlic, ginger, soy sauce, sesame oil, and ground pork to the bowl with the sautéed cabbage. Massage the mixture with your hands until it is evenly mixed and slightly sticky or tacky in texture.

Spoon about one teaspoon of the pork mixture into the center of a wrapper. Dip a finger in water and wet the outer rim of the wrapper. Fold the wrapper over the filling and pinch the edges to close (here is a video demonstrating different folding styles).

When ready to cook the gyoza, heat 1 Tbsp canola or vegetable oil in a non-stick skillet over medium heat. Working in batches, add the gyoza with the seam side up, and fry until the bottom is golden brown and crispy. Using the lid as a shield, pour about 1/4 to 1/3 cup water into the skillet and quickly place the lid on top to contain the steam and splatter. Let the gyoza steam in the skillet for 1-2 minutes, or until most of the liquid has boiled away. Remove the lid and let the gyoza cook for a minute more, or until the bottom is crispy again. Serve hot.