Cook the udon as package directs. When done, rinse, drain and set aside while the soup is cooking.
Remove and discard the shiitake stems. Reserve the soaking water and slice the caps thin. Place the water, shiitake soaking water, shiitake, wakame and daikon in a soup pot. Cover and bring to a boil. Reduce the flame and simmer for 7 to 10 minutes. Reduce the flame to low. Take 3 tablespoons of the soup stock and dilute the miso with it. Add the miso to the soup. Stir and place the udon in the hot soup to reheat. for 1 to 2 minutes. Place the udon in individual serving bowls and ladle the soup over. Garnish with the scallions and serve.
Per serving - 229 calories, 2 g fat (8% calories from fat), 10 g protein, 43 g carbohydrate, 5 g fiber, 0 mg cholesterol, 315 mg sodium