Guacamole

Method

1. Put 15 g finely chopped white onion, 1 chopped serrano chilli, half of the 5 g chopped coriander and 0.5 tsp fine sea salt into a molcajete (or a heavy pestle and mortar). Grind for 1-2 minutes, pressing and turning, until you have a coarse wet green paste — the salt draws the juices out and takes the raw bite off the onion.
2. Halve 1 ripe Hass avocado, twist the halves apart, lift out the stone and score the flesh in the shell into rough 1.5 cm cubes. Scoop it into the molcajete with a spoon. It should give easily under gentle thumb pressure at the stem end.
3. Mash the avocado into the chilli paste with the pestle or a fork, using short pressing strokes rather than stirring. Stop while it is still chunky — guacamole should be textured, not a purée.