Step 1

In a large saucepan, combine the dashi, soy sauce, mirin and sugar. Bring a large pot of water to a boil. Using your hands, add the noodles to the pot, shaking them over the baking sheet to remove excess starch. Cook, stirring often, until a noodle rinsed under cold water is tender, 15 to 17 minutes. Meanwhile, bring the dashi mixture to a simmer over medium, then remove from the heat and cover to keep warm.

Step 2

When the noodles are done, drain in a colander, rinse under warm water and drain again. Divide the noodles evenly among 4 serving bowls. Ladle in the hot broth and sprinkle with the scallions. If desired, serve with shichimi togarashi.