I am very much in agreement with Michelle - I've been making soup almost every day this week. This one is Martha Stewart's hot & sour soup - I was actually really sure I had already posted this because I've been making it since college, but it looks like I haven't. Usually I do include the tofu, but this time I didn't have any, and it was way too cold to go out and get some.
From Martha Stewart
3 cups chicken broth
2 tbsp soy sauce
1/2 tsp crushed red pepper
4 cups fresh mushrooms, thinly sliced (I usually use button but the original recipe calls for shiitake)
4 tbsp rice vinegar
2 tbsp corn starch
1 egg, lightly beaten
1 1/2 cup tofu, cubed
2 tbsp freshly grated ginger
4 green onions, thinly sliced
In a large pot, bring the broth, soy sauce, crushed red pepper and 2 cups water to a boil over medium heat. Once it's boiling, add the mushrooms and simmer for 5 minutes.
In a small bowl or cup, dissolve the cornstarch in 3 tablespoons of the vinegar. Add it to the pot and let simmer for about another minute.
Pour the egg through a slotted spoon and stir gently to make ribbons. Add in the tofu. In a small sieve or over a microplane, squeeze the juice out of the grated ginger - discard the pulp, don't add it to the soup. Taste and add the last tablespoon of vinegar if needed. Before serving, add the green onions.