Typically viewed as the dietary province of zombies, brain is a delicacy in many countries. It is often overlooked as a dish in its own right in the UK.
Brains aren't the easiest of ingredients to source in the UK. The brains from calves (cows under 12 months old), lambs (sheep under 12 months old) and pigs have been approved for consumption by the Foods Standards Agency, but the sale of cows’ and sheeps' brains (from animals more than one year old) is banned in the UK. Similarly, unless you're prepared to buy a whole pig's head and remove it yourself, it can be difficult to find pigs' brains (although pig heads are sometimes sold at Oriental stores). Lambs’ brains are probably the easiest to source - try butchers, particularly ethnic butchers, or go directly to the meat markets.
Use brains as fresh as you can, ideally on the day of purchase.
Mild and sweet with a creamy texture, brains can be served hot or cold. Before cooking they need to be soaked for at least an hour and preferably longer, in several changes of water. The membrane that covers the brain should then be peeled off and the brain poached in simmering acidulated water (white wine vinegar is the standard addition) for about 10 minutes. The brains can be cooled in their cooking liquid and served cold in a salad or dredged in seasoned flour, fried in butter and eaten warm.