If using the long pieces of wakame, rinse and soak for 10 minutes in cold water to cover. Remove and discard soaking water. Chop the wakame. If using instant wakame flakes, there is no need to rinse or soak. Place the wakame and water in a pot, cover and bring to a boil. Add onions and carrots. Cover, reduce flame to medium low and simmer 5 minutes. Reduce the flame to low. Dilute miso in 1/4 cup of the hot soup broth and add to the soup. Add bok choy, and tofu, let simmer, without boiling of 2 minutes. Serve and garnish with scallions.
Per serving - 45 calories, 1 g fat (24% calories from fat), 4 g protein, 5 g carbohydrate, 1 g fiber, 0 mg cholesterol, 336 mg sodium