‘We introduced avocado to the high street!’ How Pret conquered London – and began eyeing the rest of the world

The sandwich chain now has 274 branches in the capital. How did it grow so huge – and can anything stop it getting even bigger? At 93-95 Victoria Street, Westminster, a blue plaque marks a piece of London history: the first ever branch of Pret a Manger opened on this spot on 22 July 1986. Nearly…