Straciatella are little rags or strings, which is what the eggs look like when they are cooked. It is these gentle shreds that make this soup so comforting. The essentials of this soup are the stock, or brodo, the eggs, and the cheese. The spinach or other greens are variants. Cooked peas can be used instead of the greens and Garlic Broth can be substituted for the brodo.
The technique in this recipe is stolen, with gratitude, from Pellegrino Artusi, a brilliant cook and gastronome who wrote The Art of Eating Well.
Use a pot that is large enough to hold the colander over the stock without actually touching it, so that the egg can flow freely into the soup to form the strings.