In a salmon poacher or large saucepot, mix the sake, celery, carrot, onion, sugar, bay leaves, peppercorns, soy sauce, and water, to cover. Add the seasoned salmon and slowly bring the liquid to a simmer. Simmer for 3 minutes then turn off the heat. Let stand for 5 to 10 minutes depending on doneness desired. I prefer medium rare (5 minutes).
In a blender, add ponzu, shallots, 1/2 tablespoon togarashi, soy, and sugar. Blend on high speed and drizzle in the oil. Season with salt and pepper.
In a large bowl, mix together fennel, somen, and scallions and toss with enough vinaigrette to coat the salad. There will be some left over for plating. Check for seasoning.
Plating: On a large plate, place a mound of the salad and top with hot salmon. Drizzle on a little of the vinaigrette and garnish with remaining togarashi and fennel fronds.