Meaty king oyster mushrooms, seared until golden and scored like scallops, over chilled buckwheat soba tossed in a sweet-salty sesame sauce. It comes together in 30 minutes, and it's just as good cold from the fridge the next day. One of my most regularly-made recipes!
Whisk the soy sauce, maple syrup, rice vinegar, 1 tbsp sesame oil, and garlic in a small bowl. Transfer 3 tablespoons to a separate bowl for the mushrooms. Whisk the cold water into the remaining sauce and set both aside.
Trim the tough bottoms off the mushrooms and cut the stems into 1-inch-thick rounds. Score both cut sides in a shallow crosshatch, about ⅛ inch deep — don't cut through. Brush all over with the reserved 3 tablespoons of sauce and set aside.
Bring 3 quarts of unsalted water to a boil. Add the noodles and cook for 5 to 6 minutes, or according to package directions, until tender with a little bite.
Drain the noodles and rinse under cold running water, rubbing gently by hand to wash off the surface starch, until fully cooled. Shake off the remaining water and toss the noodles with one teaspoon of sesame oil so they don't stick. Set aside.
Heat 1 tablespoon neutral oil in a large skillet or wok over medium heat. Add the chopped green onion whites, bell pepper, and carrots and cook, stirring, until crisp-tender, 4 to 5 minutes. Transfer to a plate to cool.
Heat the remaining 1 tablespoon of oil in the skillet over medium-low heat. Add the mushrooms, scored side down, and cook undisturbed until deeply golden, about 5 minutes. Flip and cook 4 to 5 minutes more, until browned and tender all the way through.
Add the noodles and vegetables to a large bowl, pour over the sauce, and toss well to coat. Divide among four bowls, top with the mushrooms, and garnish with the reserved green onion tops and sesame seeds.
Notes
Soba noodles.100% buckwheat soba is gluten-free and has the deepest flavor, but it's pricey and more delicate. A buckwheat-and-wheat blend is cheaper, sturdier, and works beautifully here.
Rinse the noodles well. Soba releases a lot of starch. Rinse until the water runs clear to keep the salad from turning gummy.
Room temperature or cold. Both are good. If you make the salad ahead, the noodles firm up in the fridge — loosen them with a splash of water or a drizzle of soy sauce before serving.
Make ahead. The sauce keeps for 5 days in the refrigerator. It does not freeze well.