Stallholders at Rosewood London Market / Nicolas Buisson

Samuel Muston discovers a farmers' market with a philosophy

It is hard to imagine, as you duck under the straw-covered stalls selling Hansen & Lydersen salmon, Chegworth Valley juice, O'Shea's beef rib and scores of other delights, that this market, which sits in the stone courtyard at London's Rosewood Hotel, owes its entire existence to the 1986 opening of a McDonald's on the Piazza di Spagna in Rome.

This is London's first weekly Slow Food market. You might have heard the phrase Slow Food before. Perhaps you have visited one of the markets in Bristol or Norfolk, or the one that seems to pop up, quite randomly, in Edinburgh.

Slow Food, an acronym of sustainable, local, organic and wholesome, is about more than food. It is about living the good life. After that McDonald's opened in Rome 28 years ago, and 19 people died after an Italian wine-maker added methanol to his wine in an attempt to cut costs, a man called Carlo Petrini from Piedmont decided enough was enough. He worried that, since the Italian post-war boom – when meat intake increased from 22kg per person in 1960 to 62kg in 1975, and multinationals moved in to slake the thirst for the new – the traditional ways of Italian agriculture and eating were under threat. And so he set up Slow.

People quickly flocked to Petrini's banner. In December 1989, he released a Slow manifesto in a theatre in Paris. It rallied against "those, and there are many of them, who confuse efficiency with frenzy", and, proposed "the vaccine of a sufficient portion of assured sensual pleasure, to be practised in slow and prolonged enjoyment ...". There was, Slow declared, a "universal madness of the Fast Life". And the antidote was reconnection – to the land, to the people who make our food, to a world before the supermarket and the multinational burger chain.

If you walk around the stalls at the hotel, you can ask the man from Wild Hives about the bees that make his honey, you can ask Market Gourmet about the provenance of those nice-looking oysters. You don't have to come here and do your main shop. It isn't, after all, cheap. But even if you buy only a jar of honey, or nothing at all, you still think about your food in quite a different way than you do as you reach for a shrink-wrapped banana in a garishly lit superstore. You reconnect. It is a farmers' market with a philosophy.

The Rosewood London's chef, Amandine Chaignot, has been allowed to invite these stallholders in because it is likely to draw people to the hotel and its Sunday brunch, which uses the Slow market products, naturally. It is a surprising and lovely thing to find yourself momentarily in the English countryside amid the clamour and fumes of central London.