1. Put together the sifted flour, salt and corn starch into a large bowl and stir well. Add hot water and stir with chopsticks. Then knead the dough by hand for about 5 to 6 minutes until the dough gets smooth. You can shape it into a ball.
2. Let the dough sit in the bowl for about 30 mins, covered with a damp cloth.
3. Take about 10g from the dough onto lightly dusted board with corn starch. Flatten it into a round disc shape, then roll it into about 8 to 10cm in diameter circle with a rolling pin, to make circle you need to repeat turning the dough. Do not roll the dough too thin. If you want to make the dough into a perfect circle, then use a circular cookie cutter. Repeat for the rest.
4. Wrap a stack of your gyoza wrappers lightly in a plastic wrap until ready for use. Do not forget to dust each layer with a bit of corn starch to prevent them from sticking to each other!
Note: You can keep them in the freezer for about 1 month.