Just in case any of the Cambridge based forumites haven't been there, I can recommend a visit to the Cambridge Farmers' Outlet (8 Lensfield Road - opposite the Catholic church).
It has a wide range of produce all from local producers. The prices compare well to some of the supermarkets.
They also stock Bean Thinking vegetarian and vegan ready meals - absolutely lovely stuff!
It's run as a co-operative and well worth a visit.