Although there are many recipes, it is normally made with the following ingredients: sheep's heart, liver, and lungs (or "lights"), minced with onion, oatmeal, suet, spices, and salt, mixed with stock and traditionally boiled in the animal's stomach for several hours. In this it somewhat resembles other stuffed intestines, otherwise known as sausages, of which it is one of the largest types. Vegetarian recipes also exist, and the best of these make an extremely tasty haggis.
In some ways it resembles scrapple. However it differs in the following ways: it uses sheep offal instead of pig offal and oatmeal instead of cornmeal; it is a sausage rather than a meat loaf; and it is boiled instead of being baked. As a result, the appearance and the flavour are very different.
Haggis is traditionally served with the Burns supper on January 25th, when Scotland's national poet, Robert Burns, is commemorated. (He wrote a poem about the haggis). During Burns' lifetime haggis was a popular dish for the poor, since it made use of parts of a sheep that would otherwise have been wasted.
Haggis is widely available in supermarkets in Scotland all the year round, and the cheaper brands are normally packed in artificial casings, rather than stomachs, just as the cheaper brands of sausages are no longer stuffed into animal intestines. In addition, practically all Scottish fish and chips shops will sell their customers a haggis supper. This consists of a small single portion haggis dipped in batter and deep fried with chips; it provides a hot, filling, and very satisfying high-calorie meal for a cold winter's day. There are also fast-food shops that sell haggis burgers, with a patty of fried haggis on a bun.
Since many countries' food safety laws outlaw some of the ingredients in haggis, expatriate Scots and Scots descendants overseas have been known to engage in haggis smuggling to obtain true Scottish haggis.
A rumour circulated in recent years that actually 'haggis' is the name of a small four-legged Scottish Highland creature, which has the limbs on one side shorter than the other side. This meant that it could run around the hills at a steady altitude, without either ascending or descending. Therefore a haggis could be cought by running around the hill in the oposite direction. However, despite the fact that a high proportion of tourists were found to believe in this creature, no examples of the species has ever been found.