In mortar and pestle (or medium bowl) add onions and garlic and smash them against the side to get the juices out.
Add avocado, lime juice, salt & pepper and mash with two spoons to desired consistency (I don't like mine totally smooth). Taste and season to desired preference.
Stir in tomato and cilantro and serve with chips!
Recipe by One Green Fork at https://www.onegreenfork.com/guacamole/