Place the chopped white onion and the salt in a medium bowl and using the back of a spoon, crush it to release some of its juices. This should take 1-2 minutes.
Dice the peach and add half of it to the onion, similarly mashing with the spoon until slightly broken down.
Remove the seeds from the chipotle and finely chop. Stir this into the mixture, along with 1 teaspoon of the sauce from the can of chilis.
Next add one avocado, mashing again with the spoon. Stir to combine, then add the remaining avocado and the remaining peach, stirring it in gently so it remains slightly chunky. Taste for seasoning and add more salt if necessary, Sprinkle on the cilantro and serve with chips.