Head cheese, also called souse and brawn, is a jellied loaf or sausage.
Brawn is usually made from a pig's head, but sheep or ox head may be used, and in some parts of Britain rabbit is used.
In medieval Britain brawn was made from the abundant wild boar, and originally 'brawn' referred to the flesh of wild boar. Later around the 16th century when wild boar was no longer plentiful, pigs were used instead.
Originally it was made entirely from the meaty parts of the head of a pig or calf, but now can include edible parts of the feet, tongue, and heart. The head is cleaned and simmered until the meat falls from the bones, and the liquid is a concentrated gelatinous broth. Strained, the meat is removed from the head, chopped, seasoned and returned to the broth and the whole placed in a mold and chilled until set, so it can be sliced.