Roughly chop onion and garlic and puree in a food processor. Scoop out the mixture and use cheesecloth or a mesh strainer to squeeze out all the juice until it is almost totally dry.
2
Peel and remove the pits from two avocados. Place them in a container and mash the avocado with a potato masher, along with the onion mixture, until smooth.
3
Squeeze the lime into the avocado/onion mixture and stir to combine thoroughly.
4
Add the salt and the tomato and stir to combine thoroughly.
5
Store in the refrigerator with plastic wrap lying directly on the surface of the guacamole, avoiding excessive exposure to air, to avoid turning brown.
