1. Add flour, salt and rice flour into a large bowl and stir well. Add hot water and stir with a rubber spatula. Then knead the dough by hand for about 1 to 2 minutes until it gets smooth. You can shape it into a ball.
2. Let the dough sit in the bowl for about 15 min, covered with a damp cloth.
3. Remove the bowl of your stand mixer and attach the pasta roller to it.
4. Take some of the dough (about 1/3), shape into an oval. Flatten it and dust it with flour on both sides.
5. Feed the dough through the pasta roller (setting 1 - thickest), at least 3 to 5 times or until the dough is smooth. Turn dial to the thickness setting 3 or 4 and run the dough through once or twice. Repeat (once or twice) at each following position until you reach setting 8. The target thickness really depends on your own preference. I like thin skin, so I roll it until setting 8 :)
6. Lay the rolled out sheet of dough on a cutting board and cut it out, using a circle cookie cutter (8~9cm diameter suggested). Dust the cut out wrappers with katakuriko/potato starch and set aside. Repeat as many times as you can.
Gather all the scrap dough, put it all together and re-roll it a few times until it becomes thin layers again.
1. In a bowl add cabbage and 1 tsp salt, let sit for about 15 minutes. Set aside.
2. In a bowl, add all the ingredient A and cabbage (drained well from #1) and knead the mixture with hand until it becomes pale in color and sticky.
3. Place a gyoza wrapper on a cooking board. Use a teaspoon to take a small amount of filling and put it in the center of the wrapper. Wet the edge of wrapper with fingertip. Make pleats on one side, then fold over and seal to close. Continue with the rest of the gyoza wrappers until you used all filling.
4. Heat 2 tbsp vegetable oil in a large frying pan over medium to high heat. Remove from the heat once to place gyoza, and cook them until golden brown and crispy on the bottom.
5. Pour boiled water (about 100ml), cover pan with the lid and let it steam over medium heat until all water evaporates. Repeat with the remaining gyoza.
6. For the dipping sauce, mix all the ingredient in a small bowl.
7. Place a plate on top of gyoza. Flip the pan upside down. Cook the remaining gyoza.