Strain the flour and cornflour into a bowl.
Gradually pour in the boiling water and mix.
Pour in the cold water, and start kneading for about 10 minutes until all the mixture uniforms.
Place the dough in a covered bowl to rest for 15 minutes.
Knead the dough again for another 10 minutes and let rest for another hour.
After an hour, take the ball of dough and use your finger to make a hole in the center of the dough. Stretch and expand the dough slightly with your hands.
Divide the dough in the shape of the donut into 4 equal parts with a knife.
Flour the surface you are working on. Roll out the first part into a thick snake shape 15-20 cm long. Cut it into 6 equal parts with a knife.
Flatten each piece by hand into a small disc shape. Always make sure the surface is floured. Take a small rolling pin and roll it up to a thin, round thickness. Repeat with the rest of the pieces. And with the rest of the dough.
Stack all the dumpling sheets on top of one another as you make sure to flour in between each wrapper.
Make your desired filling and use the wrappers immediately, or store them in a bag and keep them in the freezer.