It’s a sun-drenched afternoon in south London, and I’m surrounded by food. No, I’m not in a supermarket or restaurant, and I haven’t just loaded up on picky bits for a park picnic. I’m in the Rookery, a community-run garden on the southern edge of Streatham Common, but if you were to see the abundant nature around me – branches peppered with olives, creeping tomato vines bursting with ripe, juicy fruits and towering cherry trees against a cloudless blue sky – you’d think I washellip;read more raquo;