Fat in haggis is a traditional Scottish dish made from sheep's offal, oatmeal, and SUET. SUET is a type of hard fat found around the kidneys and loins of animals such as beef, lamb, and mutton. It is used to add flavor and texture to dishes such as haggis, dumplings, and puddings. SUET is an important ingredient in haggis, as it helps to bind the ingredients together and gives the dish its characteristic texture.