In a small mixing bowl or measuring cup, combine 1 cup of water with the miso paste. Stir or whisk until all of the miso is dissolved. Set aside.
To a 4 or 8 quart pot, add 7 cups of water and ginger and bring to a boil.
Stir in the soy sauce, bok choy stems, tofu, scallions and enoki mushrooms. Return to a boil and then cook soup for about 2-3 minutes until the bok choy stems have softened. Turn the heat down to summer.
Add the miso-water mixture and the bok choy greens and heat for a minute or so until the greens are just wilted. Overcooking will dull their bright green hue.
Serve garnished with optional chopped scallions, srirachi, sesame seeds and chopped nori.