Ask any two people and very few will agree how to make guacamole. That's ok! This is an easy guacamole recipe, but you can build on it to suit your tastes.
Put the avocado in a wide, flat-bottomed bowl and mash with a fork until almost all the avocado is smooth leaving a few chunkier pieces for texture.
Add the onion, coriander and lime juice and season with salt and pepper then mix together. Taste and adjust the seasoning, adding more lime juice if you like. Stir in the chopped red chilli, if using. Serve immediately.