Avocados are native to Mexico, where they are used as more than just an ingredient in a chip dip. Here I'll show you three stages of making guacamole, from the most simple and delicious version to an elegant dip to serve your guests.
Cut around each avocado lengthwise, then twist the two halves apart. Remove the pit and scoop the avocado flesh into a bowl. Mash the avocados (preferably with an old-fashioned potato masher) into a coarse purée. Season the purée with salt, about 1 teaspoon. Mince the clove of garlic. Sprinkle the minced garlic with a little salt, and mash with the side of your knife into coarse paste.
Fold in the lime juice and chopped cilantro.
Mince the green chile and add the desired amount to the bowl. Chop the tomato and add to the bowl. Mince the onion (you should have about a third of a cup) and rinse under cold running water in a small mesh strainer. Shake off the excess water, and mix into the avocado.
If you aren't serving the guacamole immediately, cover with plastic wrap directly on the surface of the guacamole and refrigerate. For best results, make the guacamole within 2 hours of serving and serve in batches.