In a small bowl, combine 2/3 cup flour and salt. Make a well in the center. Beat egg and cold water; pour into well. Stir together, forming a ball. , Turn dough onto a floured surface; knead for 8 minutes, adding remaining flour if necessary to keep dough from sticking to surface or hands. Cover and let rest for 10 minutes. , On a lightly floured surface, roll dough into a 12x8-in. rectangle. Dust top of dough with flour to prevent sticking while rolling. Trim the edges. Dust both sides of dough with flour. Roll up jelly-roll style; cut into 1/4-in. slices. Separate and unroll the noodles; let rest on a clean towel for 1 hour. , In a large saucepan, bring water to a rapid boil. Add oil and noodles; cook for 7-9 minutes or until tender. Drain and serve immediately. ,