1 tbsp. kosher salt
3 cups udon flour
1. In a bowl, stir together 2⁄3 cup plus 2 tbsp. warm water and 1 tbsp. kosher salt. Put 3 cups udon flour into another bowl; pour in water. Stir until crumbly and form into a ball. Seal dough in a plastic bag; let rest for 30 minutes. Knead dough until smooth, about 15 minutes.
2. Roll dough out to a thickness of 1⁄8". Sprinkle liberally with flour.
3. Gently fold the dough into pleats, making 4 or 5 folds.
4. Cut the dough into 1⁄4"-thick ribbons. Dust with flour; cook noodles (see Cold Udon).
MAKES ABOUT 1 LB.