Tower Bridge glints in the sunlight. The Thames is sparkling in the heat and echoing the hum of a regatta and the final few vuvuzelas of The World Cup. The Mayor is somewhere nearby in the heart of London and we are in the thick of it, pitched out like the world’s greatest picnic to celebrate the greatness of Rioja. It may sound unusual to imagine a festival of tapas in the heart of London with oodles of stalls, chefs, wineries and partygoers soaking up the sunny atmosphere. But this year was the best festival yet...