Well, I also made it to the farmer's market in Stoke Newington a few weeks ago. There was a really nice atmosphere and all the stallholders were friendly answering my questions about weird breads and the possibility of finding some grains around.
My friend from back was visiting at the time, so I had a great time showing her around London. It was quite by surprise that we even found the market, but it's on every Saturday 10am-2.30pm. Maybe I'll see you there this Saturday?
The deets: The veg boxes that Growing Communities sell are by far the cheapest if you live around Hackney. In our flat it's quite helpful that we have 2 full days to pick up the bag rather than trying to make sure someone's home. There are so many nice places to pick up from - Hackney City Farm, cafés and green grocers. Next month I think we'll change to an organic grocery store so we can stock up on a few other good things at the same time. It's supposedly one of the benefits of (comparatively expensive) Abel & Cole that's there's a great pantry to choose from. The standard veg bag keeps our flat well stocked for the week, but then 1 out of 4 has been too stressed to cook slash away since we started on the scheme. The no pots bag is definitely worth considering if you're like the rest of our generation - pasta is just all we know, and we should admit it like Fred in Portlandia.