Gather all the ingredients.

Cut the thick core from ¾ lb green cabbage and cut the leaves into ⅓-inch (1 cm) strips. Finely chop crosswise. Pay extra attention to the thick white ribs—mince them until very fine. Sprinkle with 1 tsp Diamond Crystal kosher salt and rub it in with your hands. Transfer to a bowl and let sit until wilted.

Mince 2 green onions/scallions into small pieces. Cut off the stems from 2 shiitake mushrooms, thinly slice the caps, then mince the slices into small pieces. Grate the ginger with a ceramic grater and add 1 tsp ginger (grated, with juice) to a small plate. Mince or press 2 cloves garlic and add to the plate.

Add ½ lb ground pork, the green onions, and the shiitake mushrooms to a large bowl. Add 2 tsp sake, 2 tsp toasted sesame oil, 2 tsp soy sauce, ⅛ tsp freshly ground black pepper, the ginger, and the garlic. Put on plastic disposable gloves if preferred, then knead the mixture until sticky and pale.

Squeeze the water from the salted cabbage and add to the pork mixture. Knead the filling until the cabbage is fully incorporated and the mixture is uniform.

Prepare a small bowl of water and a baking sheet lined with parchment paper or dusted with 2 Tbsp potato starch (or cornstarch). Open 1 package gyoza wrappers and cover them with a damp towel or plastic wrap at all times.

Hold one wrapper in the palm of your non-dominant hand. Measure 1 level Tbsp of filling with a small cookie scoop. Place the filling in the center of the wrapper and flatten it with the scooper bowl to press out any trapped air. Dip one finger in water and use it to moisten a circle on the wrapper's outer ¼ inch.

Fold the wrapper in half over the filling. Pinch the two sides together at the top center, but don’t seal it yet. Starting to the right of top center, fold a pleat leaning toward the center into the top half of the wrapper using your right thumb and index finger. Tightly press the folded pleat against the back half of the wrapper using your left thumb and index finger. Fold 2–3 more pleats on the right side ¼ inch apart. Press to seal any gaps.

To the left of top center, fold a pleat leaning toward the center into the top half of the wrapper using your left thumb and index finger. Tightly press the folded pleat against the back half of the wrapper using your right thumb and index finger. Fold 2–3 more pleats along the left side every ¼ inch.

Press one last time to seal any gaps and secure the pleats. Evenly distribute the filling and make the bottom flat so the gyoza sits upright. Place on the baking sheet and cover with plastic wrap to avoid drying. Fold the remaining gyoza.

Heat a large nonstick or carbon steel frying pan over medium heat. When hot, add 1 Tbsp neutral oil. Dust off any potato starch from the gyoza bottoms with a pastry brush.

Place the gyoza in the pan, flat side down in a single layer in a circular pattern. Leave space between each piece so they don‘t touch. Cook about 3 minutes, until the bottoms are golden brown and release cleanly from the pan.

Add 4 Tbsp water to the pan and immediately cover with a lid. Steam for about 3 minutes, until most of the water evaporates.

Remove the lid and cook until the water fully evaporates, about 1 minute. Drizzle 1 tsp toasted sesame oil around the gyoza and cook, uncovered, until the bottoms are deep golden and crisp.

Transfer to a plate and serve with a side of dipping sauce. For each serving, mix 1 Tbsp rice vinegar, 1 Tbsp soy sauce, and optional ⅛ tsp la-yu in an individual sauce plate or bowl.