- 2 cups unseasoned dashi (Japanese soup stock)
- 5 tablespoons usukuchi shoyu (Japanese light soy sauce)
- 3 tablespoons sugar
- 2 tablespoons mirin (Japanese sweet rice wine)
- 1 1/2 shoyu (Japanese soy sauce)
- 3 bundles somen (thin white wheat noodles), paper wrapping discarded
- Accompaniments: finely grated peeled fresh ginger; minced scallion; shredded fresh shiso leaves; sesame seeds
- Heat all dipping sauce ingredients in a small saucepan over low heat, stirring, until sugar is dissolved. Cool sauce, then chill, covered, until cold, about 1 hour.
- Bring 2 1/2 quarts water to a rolling boil in a 4-quart saucepan over moderately high heat. Add noodles and 1 cup more water. When water returns to a boil, add 1 cup cold water and bring back to a boil. Simmer noodles until just tender and slightly translucent, about 2 minutes. Test noodles for doneness by dipping 1 strand in cold water and sampling. If noodles are not tender, add 1 cup more water and return water to a boil. Drain noodles in a colander and rinse well under cold water.
- Divide noodles among 6 bowls filled with ice and cold water. Divide dipping sauce among 6 small bowls and serve with accompaniments for flavoring it, then dip each mouthful of noodles in sauce.