Use either a pestle and mortar to grind up the onions and chilli (and garlic if you are using), or simply chop these up and add the avo,  mashing with a whisk.  Add the cilantro/coriander and lime juice, checking the seasoning as you go by tasting and adding extra if you think it needs it Do the same with the salt and pepper. Add the pomegranate seeds at the end stirring most of these through but reserving a few to decorate the top.

Serve with corn chips for dipping.