(From stickyrice.com)

Miso Soup

Miso is one of Japan's most important staples. Miso soup is served for breakfast, lunch, or dinner and is packed with protein.Miso is basically a mixture of crushed and boiled soybeans, wheat, barley or rice that is injected with a yeast mold and then allowed to mature over months or even years. There are a few different forms of miso, each having its own flavor, color, and texture. Yellow miso is fairly sweet and used in dressings. Dark miso is used in strong, chunky soups. And finally there is the red miso, which is excellent for winter soups. This is what we will use for our soup.

Ingredients
1 small leek, washed and trimmed
2 shitake mushrooms, sliced
1 piece (4-6 inches) dried kombu, wiped
3-5 packets (0.175 ounces each) dried bonito flakes
A few strands dried wakame seaweed
4 ounces fresh tofu (about 1/3 of a cake)
2 Tablespoons red miso

Prepare the soup
1. Slice the leek into fine strips.
2. Slice the shitake mushrooms.
3. Cut the tofu into 1/2 inch cubes.
4. To make the soup stock, put the kombu into 7 1/2 cups cold water 
and bring to a simmer (careful not to boil kombu since this makes it 
bitter). Remove any surface scum that forms. Add 2 or 3 packets of
the bonito flakes and simmer uncovered for about 20 minutes, until
the stock is well reduced. Add another 1 or 2 packets of bonito
and quickly remove from the heat. Allow the flakes to settle to the 
bottom and then strain.
5. Warm the stock back to a simmer. Break the wakame seaweed into 
small pieces (trim off the tough stem if necessary). Add leeks, 
mushrooms, tofu cubes, and wakame pieces and simmer for 2-3 minutes 
until leeks and mushrooms are cooked. Dissolve the miso in a few 
tablespoons of the hot stock, blending it with a wire whisk. Stir half
the mixture into the soup, then taste and add sufficient of the rest 
to make a rich well-flavored soup. Heat until nearly boiling.
6. Ladle the soup into 4 warmed soup bowls, distributing the leek 
slices, mushrooms, wakame, and tofu evenly, and serve immediately.

Serves 4