1. Cut the avocados in half. With the tip of a small knife, loosen the seeds and lift them out. Remove any brown tissuelike fibers that cling to the flesh. Strip off the skins with your fingers or the knife, starting at the narrow or stem end.
2. Chop the avocados coarsely; then, in a deep bowl, mash them to a rough puree. Add the tomato, half of the chopped eggs, the onions, chilies, lime juice and salt, and mix them together gently but thoroughly. Taste for seasoning.
3. Mound the guacamole in a serving bowl, scatter the remaining chopped eggs over it and, if you are using it, sprinkle the coriander on top. Serve at once, accompanied by the tostaditas.
