1. Mash the garlic and salt together in a mortar and pestle. (You can also make guacamole in a bowl using a fork or potato masher. If so, chop the garlic first.) Split the avocados in half and remove the pits. Scoop out the pulp with a soupspoon and dice the pulp, then add it to the garlic and mash it into the garlic along with the lime juice.
2. Mash the guacamole so it’s to your liking – some like it chunky, some prefer it smooth – then mix in the onions, cilantro, some chopped fresh chili, and olive oil, if using. Taste and season with more salt, lime juice, and chile if desired. For a slightly smoky flavor, add a bit of chipotle or ancho chile powder.