Cold soba noodle salad with cucumber and shiitake

1 pound shiitake mushrooms, stems discarded
8 scallions
3 tablespoons peanut oil
Salt and freshly ground pepper
3 tablespoons light soy sauce
2 teaspoons freshly grated ginger
2 teaspoons minced garlic
1 teaspoon Asian sesame oil
1/2 teaspoon rice vinegar
1/2 teaspoon chili oil
7 ounces soba noodles
1 large cucumber—peeled, halved, seeded and cut into thick matchsticks
2 teaspoons black sesame seeds (optional)

Light a grill or preheat a grill pan. In a large bowl, toss the mushrooms and scallions with the peanut oil and season with salt and pepper. Grill the mushrooms over moderate heat, turning once, until cooked through and tender, about 4 minutes; transfer to a plate. Grill the scallions, turning once, until softened and blackened in spots, about 2 minutes; add to the mushrooms. Let the mushrooms and scallions cool, then thinly slice them. (or sautée mushroom and scallions in a pan in the peanut oil)
In a small bowl, whisk the soy sauce with the ginger, garlic, sesame oil, rice vinegar and chili oil.
In a large pot of boiling salted water, cook the soba noodles until al dente, about 4 minutes; drain. Transfer the noodles to a large bowl. Add the mushrooms, scallions, cucumber and dressing and toss well. Sprinkle with the sesame seeds and serve.

Recipe adapted from Food and Wine magazine