Chilled Soba with Tofu and Sugar Snap Peas

MAKE SAUCE

Step 1

Simmer the mushroom in the water in a small saucepan, covered, for 15 minutes. Add the kombu and barely simmer, covered, 5 minutes more. Remove from heat and let stand, covered, 5 minutes. Strain liquid through a fine-mesh sieve into a large glass measure, pressing on and discarding solids.

Step 2

Return 2 cups liquid (add water, if necessary) to the saucepan. Add the soy sauce, mirin, ponzu, sugar, and 1/4 teaspoon salt and bring to a boil, stirring until sugar has dissolved. Remove from heat. Stir in the sesame oil, then cool in the pan set into a large ice bath.

COOK NOODLES AND VEGETABLES

Step 3

Blanch the snaps peas in a large pot of unsalted boiling water until crisp-tender, about 2 minutes. Transfer with a slotted spoon to a large colander set into an ice bath to stop the cooking. Lift the colander to drain, then transfer peas to a bowl.

Step 4

Meanwhile, return the cooking water to a boil. Blanch the spinach until just wilted, about 30 seconds, then cool and drain in same manner. Squeeze out excess water. Add to the peas.

Step 5

Return the cooking water to a boil. Add the noodles and cook according to package directions, stirring occasionally, until tender. Drain in a colander and rinse with cold water. Cool in an ice bath until very cold (add more ice to water as necessary). Drain well.

Step 6

Carefully drain the tofu and pat dry. Cut into 3/4-inch cubes.

Step 7

Whisk the sauce, then pour 1 1/2 cups sauce into a large bowl. Add the noodles, sugar snaps, spinach, and half of the onions and toss.

Step 8

Serve in shallow bowls, topped with tofu, remaining scallions, and ginger. Drizzle with some of the remaining sauce and serve remainder on the side.

DO AHEAD

Step 9

The SAUCE can be made 3 days ahead and chilled.