Weigh Ingredients: Weigh out all your ingredients accurately using a kitchen scale.
Make Kansui: Mix together water, egg, sodium carbonate, and salt to create your kansui blend.
Incorporate Kansui into Flour: Gradually add your kansui to the flour a bit at a time, mixing with your hands to ensure everything is fully incorporated.
Rest the Dough: Once the kansui is fully incorporated into your flour, transfer the dough into a ziploc bag and let it rest on the counter for 1 hour.
Knead the Dough: Knead the dough into a flat sheet by stepping on the bag. Once flattened, fold the dough over once to laminate, remembering the direction of the fold.
Rest the Dough Again: Let the dough rest on the counter again for 1 hour.
Roll Out the Dough: Cut the dough in half and roll out as thin as possible, resting the dough again if necessary to relax the gluten before achieving the final thickness.
Cut the Noodles: Roll up your dough sheet in the direction you laminated and cut it into thin strips with a kitchen knife, using a block of wood behind the knife for straight, even cuts.
Prepare Temomi Style Noodles: Unroll your noodles and dust with potato starch. Smash them into your cutting board to make temomi style noodles.
Cook the Noodles: Cook time for noodles will depend on thickness. Noodles at 1.5mm thickness take between 2.5 to 3 minutes to cook.
Serve: Strain noodles well and add them to your soup.