For the black cod: Combine the miso paste, dashi and kombu with 1 gallon of water in a stockpot and bring to a simmer. Cook, 5 minutes, then remove the kombu. Transfer some of the broth to a shallow pan and add the cod. Cook, keeping the heat at a very low simmer, covered, until cooked through, about 7 minutes.
For the vegetables: Preheat the oven to 375 degrees F. Fill a large bowl with ice water and set aside. Bring a large pot of heavily salted water to a boil, then add the bok choy and cook, 30 seconds. Transfer the bok choy to the ice bath. Set aside.
Slice the crimini and shiitake mushrooms. Remove the stems from the beech and honshimeji mushrooms. Drizzle some oil over the mushrooms and sprinkle them with salt and pepper. Roast until charred on the edges, about 20 minutes.
For the cilantro oil: Meanwhile, blend the cilantro with the oil in a blender on high for 3 minutes. Set aside.
For the pickled onions: Bring the sugar, vinegar, 1 cup water and 1 cup salt to a boil in a small saucepan. Place the onions in a medium bowl and pour the liquid over. Let steep 10 minutes.
For serving: Arrange 2 to 3 bok choy leaves on each of 4 plates. Top each with a piece of cod and add some broth. Add some mushrooms and drizzle with cilantro oil. Garnish with salmon roe, togarashi, scallions and pickled onions.
This recipe was created by a contestant during a cooking competition. It has not been tested for home use.