Place the water and shiitake in a medium saucepan, cover and bring to a boil. Reduce the heat to medium-low and simmer about 10 minutes. Remove the shiitake and remove and discard the hard mushroom stems with a knife. Slice the shiitake and place back in the pot together with the crumbled bonito flakes. Bring to a boil, reduce the heat to low and add the wakame flakes, Chinese cabbage and puréed miso. Simmer on low, without boiling for 2 to 3 minutes. Ladle into serving bowls and garnish with green onions.
Per serving - 43 calories, 1 g fat (15% calories from fat), 3 g protein, 7 g carbohydrate, 3 g fiber, 0 mg cholesterol, 337 mg sodium