Mexican-Ish Refried Beans

This is one of those dishes that totally steals the thunder in a meal: it is very moreish to the extent that it is all too easy to fill up on it and eschew the main feature. It is, of course, the secret ingredient of many a more complex ensemble (think tacos, fajitas). My version is a real Mexican salmagundi, as I have thrown all the classic ingredients of Mexican food into one dish: sweetcorn, avocado, nachos, sour cream...

Original muchachos would use pinto beans, but you c