It’s a sunny lunchtime in Milan and Ratanà’s restaurant terrace hums with the chatter of affluent office workers from nearby Porta Nuova. Today’s hot topic is not the latest vogue-ish ingredients – the artisan pecorinos and Chianti naturales – but the elegance with which chef Cesare Battisti elevates the overripe, the discarded and the stale. My son declares his Milanese meatballs, formed from meat cuts first used to make a broth (and tenderised in the process) “nicely melty”. “Delizioso!” our neighbour exclaims into her asparagus risotto, a verdantly green creation assembled from recovered asparagus ends.

Ratanà is one of a growing number of low and zero-waste restaurants, cafés and stores springing up in a city that hopes to be a model for the circular urban economies of the future. The city’s bold “zero-waste” food policy, now in its seventh year, has created five zero-waste neighbourhoods across Milan in which supply chains are shortened, commercial zero-waste initiatives are encouraged and unused edible food is collected and redistributed to those in need. Every household is provided with a 120-litre biowaste bin, from which inedible food scraps are converted into biogas to fuel city vehicles and make plant fertiliser, offered free to gardeners and farms.