The British pork pie and its relative, the veal and ham pie, are survivals of the medieval tradition of raised pies, and have changed surprisingly little. This particular pie, simply known as ‘pork pie’, is of a form distinct from other pies which merely happen to be made with pork. The filling is of fresh pork without other major ingredients, seasoned with salt, pepper, and a small quantity of herbs, especially sage.
At Melton Mowbray in Leicestershire, long famous for its pork pies, anchovy essence was added not only for its flavour but because it was thought to give the meat an attractive pink colour, while pies from other districts were brownish or greyish. In modern pies, which are always pink, the colour is achieved by the use of chemicals.
The case is made from a hot water paste of flour, lard, and boiling salted water, well kneaded to give it strength. A small hole is left in the centre of the lid. Traditionally there was a decorative rosette around the hole. Sometimes hinged corsets are used to stop the case of the pie from sagging during baking.
Present-day pies are almost always supported, so that they have sheer vertical sides, whereas those of former times used to bulge slightly. The support is removed towards the end of baking to allow the pastry to brown. Once the pie is baked, and while still hot, rich stock made from trimmings is poured through the hole by means of a funnel. When the pie cools the stock sets into a protective jelly.
Pork pies are circular when small or medium sized, and are also made as long, rectangular ‘gala pies’ - for a gala or miners’ festival. Large pies used to contain eggs and sometimes pickled walnuts; but now eggs are more usual in veal and ham pies, and walnuts are never used.
Davidson, Alan (2009) The Penguin Companion to Food, London, Penguin