All the US bases in the Uk have a commissary which is a small supermarket full of imported foodstuff. (at their price point too!)
Worked in RAF Croughton nr Biscester years back and this is where I first found out that the Americans had perfected: cheese.....in an areosol !
http://en.wikipedia.org/wiki/Easy_Cheese
However we're not allowed to buy from these shops so you will need to get friendly with a US services person and hope they will do some shopping for you
