Wakame is a green, leafy sea vegetable high in calcium and other minerals. Sea vegetables like wakame are purchased dried in packages and reconstituted in water. This hearty soup is excellent when a family member is fatigued or feeling ill. Don't let the vegetables and tofu overwhelm the broth — this should be a very light soup.
Place wakame in a small bowl of cold water and soak for 5 minutes. Put water, potato and carrot in a 4-quart pot; bring to boil.
Remove wakame from water and tear into pieces, removing the spine. Add wakame to soup. Lower heat, cover pot and let soup simmer 15-20 minutes, until vegetables are tender.
Near the end of cooking time, add bok choy and tofu cubes and let them simmer for 2 or 3 minutes.
Ladle about ¼ cup of broth from the soup into each of 4 soup bowls. Dissolve 1 tablespoon of miso into the broth in each bowl. Add more broth with plenty of vegetables to each bowl and stir gently. Garnish each bowl with scallions.
For babies 6 months and older: Remove boiled potatoes or carrots from soup after it simmers and mash with fork. Baby will benefit from the nutritious broth made by the seaweed.
For babies 10 months and older: Those that can handle soft things to chew can enjoy some pieces of cooked vegetables and tofu cubes from the soup.