In a typical recipe, the haggis ingredients, including the organ meats, are cooked and then chopped, seasoned and enclosed in the stomach lining, which is then tied with cooking twine. The trussed haggis is then simmered for several hours.
The stomach must be soaked in salted water before preparing the haggis, and in some preparations it is turned inside out before filling. The stomach must be pierced a few times before cooking the haggis so that steam will escape, otherwise it could burst.
Haggis is traditionally served with mashed potatoes and puréed turnips, a combination known as "tatties and neeps." The spices used in seasoning a haggis usually include cayenne pepper, allspice and sometimes nutmeg.
For formal occasions, the cooked haggis can be served on a platter with the stomach casing split open. Or portions of haggis can be scooped out and served on individual plates.
Modern haggis recipes can involve cooking the haggis ingredients in an artificial casing, or simply baked in a loaf pan using no casing at all.