Chilled Zaru Soba w Dipping Sauce

12 ounces dry soba noodles, preferably 80 percent buckwheat
Salt
1 cup instant dashi (kelp and bonito broth), prepared according to package instructions
1/2 cup plus 2 tablespoons shoyu soy sauce
1 tablespoon rice vinegar
1/4 cup mirin (sweet Japanese wine) - can substitute with water and brown sugar to taste
3 tablespoons katsuobushi bonito flakes, if available
1 sheet nori seaweed, toasted lightly over a gas flame and julienned
1/4 cup finely sliced scallions, for garnish
1/4 cup finely grated daikon, for garnish
Wasabi

Bring a large pot of water to a boil over high heat. Add the soba and reduce the heat to medium. When the water comes back to a boil, stir the noodles with chopsticks and add about 3/4 cup cold water. When the water returns to a boil, add more cold water and repeat this process one more time. Cook the noodles until slightly al dente, 6 to 8 minutes. (If using soba with a high percentage of wheat flour, cook it in boiling water without adding cold water for about 6 minutes.) Drain the soba and rinse under cold running water, running your fingers through the noodles to untangle.

Transfer the soba to a tray lined with paper towels and drain until dry. Place in a bowl and refrigerate, covered, until cool. If the noodles clump together, rinse and dry again.

In a small saucepan, combine the dashi, soy sauce, rice vinegar, and mirin and bring to a simmer. Add the bonito flakes and remove from the heat. After 5 minutes, strain the sauce into a serving bowl, cool, and chill.

To serve, divide the soba among Japanese bamboo baskets or rustic ceramic bowls, and sprinkle each portion with toasted nori. Serve the garnishes and individual small bowls of the dipping sauce on the side. To eat, either grab a tangle of soba with chopsticks and dunk it in the dipping sauce bowl, or spoon some dipping sauce over your portion.

Cook's Notes: When buying dried soba at Asian or health food stores, you may or may not be able to figure out the percentage of buckwheat to wheat flour from the package label. Sometimes the labels are only in Japanese, sometimes they just don't say. Unless you know a good Japanese grocery store, the best bet for high-quality 80 percent buckwheat soba (hachiwari soba) is to mail order it (see Resources below).