Cook a meal from ingredients grown within ten miles

Halfway through the shop you realise the butter is out — the nearest dairy herd turns out to be forty miles off, not ten. What's left is a meal the colour of the field it came from: potatoes, onions, a marrow the size of a forearm, eggs from a hen you can see from the kitchen window. Salt and oil don't count, so you cook with the vegetables' own water and whatever fat a farmer at the market spares you. Ask any stallholder where something came from and they'll usually tell you to the field. By October you've eaten a meal that is basically a map of the district.