But after an extensive search around London, I found what I was looking for. Sandwiched between London College of Fashion and a Hackney bodybuilding gym is a thin slice of grass. Here the patch of turf spills out peas, garlic, radishes, Scotch bonnet peppers, beetroot, broad beans, and ? thank goodness - tufts of wheat. I am so relieved.
Getting to this point involved knocking on lots of doors. Spitalfields City Farm didn?t have enough wheat to share; at Surrey Docks, there was none; the team at Stepney?s Farm said they were growing a patch with a local primary school - but they would be using to bake their own Stepney Loaf.
And then, finally, a 26-year-old structural engineer called Natalie Mady tweeted a grainy mobile phone photo of a bundle of amber wheat saying it needed to be milled.
?Before, it was just being used for dog walkers, and drunks would come in here. Nothing was really happening,? says Mady who after being given a packet of seeds from the Real Bread Campaign, helped transformed this patch of land in Hackney ? now known as Cordwainers Garden - with a few local gardeners and volunteers.
?We started putting in raised beds, adding a pond and bee hives, and building a shed, and it?s all grown from there,? she adds.
Here among mad plants and marigolds destined to become natural dyes for a Fashion College student?s garments, wheat has shot up; the garden is a perfect little sun trap.
This year, wheat has returned ?of its own accord,? Mady says, insisting I take an armful home with me.
With a cotton sack overflowing with wheat I climb onto the underground and head off in search of my next stop: a mill, to turn it into flour.
Follow Matt?s progress on Twitter as he tries to make a London Loaf. @mjponsford
READ THE FOOD BLOG: CAN YOU MAKE A LONDON LOAF: PART 1