When I think of city farms in London I think of tiny replicas of country farms – a few animal pens here and there, a few veg boxes, a farm cafe perhaps. What I don?t picture is what I find at GrowUp Urban Farm in Beckton, E6, which is essentially a warehouse divided into two main rooms, one with huge blue circular tanks filled with tilapia fish swimming around inside, and the other with silver shelves stacked on top of each other and brimming with bright green micro coriander, sunflower shoots and baby kale. On a trip there last week it felt as if I?d been jolted into the future.