In a blender combine garlic, pickled ginger, soy sauce, honey, vinegar, mirin, honey mustard, and sugar. Blend until pureed. Slowly drizzle in oil until emulsified. Hold refrigerated until service.
Trim mushroom stem and cut into three equal sections. Swallowly score 1/4" hash marks on both sides of the cut end of mushroom stems.
For each serving, heat 1 tablespoon oil in a sauté pan until shimmering. Place three sections of king oyster stems scored side down. Sear until golden brown on both sides.
While king oyster stems are searing, in a bowl combine 3/4 cup cooked soba noodles with 1/3 cup bell peppers and 2 tablespoons scallions. Drizzle with 2 tablespoons Pickled Ginger Vinaigrette and toss until well coated. Plate as desired. Garnish with bok choy leaves and set aside.
Remove mushroom "scallops" from pan when finished searing. Add 2 tablespoons soy sauce, 1 tablespoon honey, and 2 teaspoons miso. Bring to a boil, reduce heat and cook until glaze consistency. Return "scallops" to pan and coat in glaze. Place decoratively on top of soba noodle salad and drizzle with remaining glaze. Serve warm.