Cut avocadoes in half and remove pits. Scoop insides into a bowl.
Add salt, garlic, and juice from lime.
Dice tomatoes and add them to the mix. Cut onion into fours and add one portion to an electric chopper. Pull off a bunch of cilantro and add it to chopper, as well. Add cilantro and onion to dip and mix thoroughly.
Tip: Avocadoes can start turning brown quickly. Reserve a pit and put it in the dip to keep it fresh longer.