A farl (reduced form of the Scotsfardel) is any of various quadrant-shaped flatbreads and cakes, traditionally made by cutting a round into four pieces.
In Northern Ireland, the term generally refers to soda bread and to potato bread or cakes (potato farls). While soda bread can also be baked as a normal loaf, that used in an Ulster fry breakfast is made as farls (that is to say, flat rounds about 3/4 inch thick which are then cut into quarters). Modern commercially mass-produced potato farls, however, are often rectangular in form.
In Scotland today, the word is used less than in Northern Ireland, but a farl can be a quarter piece of a large flat scone, bannock, or oatcake. It may also be used for shortbread when baked in this particular shape.
The word may be related to fallaid in some way. [weasel words] However, the Dictionary of the Scots Language says that farl is a shorter form of fardel, the word once used in some parts of Lowland Scotland for "a three-cornered cake, usually oatcake, generally the fourth part of a round". In earlier Scots fardell meant a fourth or quarter.[dead link]
A farl is made by spreading the dough on a griddle or frying pan in a rough circular shape. The circle is then cut into four equal pieces and cooked. Once one side is done the dough is flipped to cook the other side.