Whisk all the ingredients for dipping sauce until the sugar dissolves. Refrigerate until ready to serve
Remove the hard stems from the cabbage, use the frilly leaves and cut into long strips. Toss the cut cabbage with 1/2 tsp of kosher salt and let it sit for 20 minutes to let the salt draw out the excess moisture. After that squeeze the excess water out with your hand and set aside
Mix all the filling ingredients together with the cabbage and mix well. Prepare a small bowl of cold water. Lay one piece of wrapper on a dry work surface and place about 1 scant tablespoon of the filling in the center. Using your index finger, run a thin layer of water along half of the inner rim and press both sides together to create a tight seal, forming the shape of a half circle. You can also pleat the dumplings. Continue to work with the rest of the filling
In a large skillet with a lid, place about 1 Tbsp of vegetable oil and heat on medium heat until hot. Carefully place the gyoza (pleat side up) in the skillet, as much as you can fit, but don't overcrowd. Cook until the bottom is brown but not burn, about 3 minutes. You may flip them over to check. Once they have browned, get yourself ready with the lid and the 1/4 cup of chicken stock. Pour the chicken stock into the skillet and immediately it will sizzle and hiss and cover with a lid. Turn down the heat and let it simmer for another 2 minutes
Open the lid after 2 minutes and the gyoza should be slightly transparent and the filling should be firm. Remove the lid and turn up the heat. Let the stock evaporates and add 1 teaspoon of oil on the gyoza and continue to cook until the bottoms become crisp, about 2 minutes. When you tilt the skillet, the gyoza will slide, remove the cooked gyoza and continue cooking with the rest of the gyoza following the steps above. If they don't slide, don't panic. remove the skillet from the heat. Place the lid back on and wait for a moment before removing them, they will be easier to be removed after that. Serve hot with the dipping sauce
Notes
Use a meat grinder to grind the pork if you have one. Otherwise, the ground pork is always available from the grocery store. Do not use food processor, as it will turn the meat into a paste.