Miso Soup with Watercress and Shiitakes

Miso, a Japanese flavoring, is made by
fermenting cooked soybeans.
White and yellow misos are mild;
dark varieties have more complex flavors.

Ingredients:
1 tablespoon olive oil
1 yellow onion, finely chopped
3 plum (Roma) tomatoes, peeled and seeded, then diced
1 tablespoon peeled and finely chopped fresh ginger
3 cloves garlic, minced
4 cups vegetable stock or broth
2 tablespoons white miso
1/4 pound firm tofu, drained and cut into 1/4-inch cubes
3 ounces fresh shiitake mushrooms, stemmed,
brushed clean, and caps thinly sliced
1 cup watercress leaves
1 green (spring) onion, including tender green top, thinly sliced

Directions:
In a large saucepan, heat the olive oil over medium heat.
Add the yellow onion and saute until soft
and translucent, about 4 minutes.
Add the tomatoes, ginger and garlic
and saute until the tomatoes
are softened, about 5 minutes.
Add the stock and bring to a boil.
Reduce the heat to a simmer.
Whisk in the miso until dissolved.
Add the tofu, mushrooms and watercress
and simmer until the tofu is heated through
and the mushrooms and watercress are softened,
about 1 minute.
Ladle into warmed individual bowls
and garnish with the green onion.
Serve immediately.