1. In a 3- to 4-quart pot, bring 2 quarts of water to a boil. Add the soba and, stirring occasionally, cook for 6 to 7 minutes, until very soft. Drain the noodles in a colander and quickly run cold water over them.
2. Drain again and divide the noodles among 6 serving bowls (the Japanese would use zaru, which are round, curved bamboo baskets), and top with crumbled nori. Garnish each bowl with scallions and a teaspoon of wasabi paste.
3. Serve the dipping sauce separately, in individual small bowls or dishes. Traditionally, the wasabi and scallions are mixed into the dipping sauce to the individual diner's taste.
