Gravy is a sauce made from the juices and residues left in the pan after roasting meat or poultry. The fat is poured off and the pan deglazed with a good stock and/or a suitable wine. This may or may not be thickened with flour. For added flavour, roast the meat on two halves of onion. Today, regrettably, gravy often comes out of a packet. Originally, gravy was a sauce made from broth and a thickening agent such as ground almonds.