Haggis is best grown from cuttings from the parent tuber than from seeds. Make sure that you buy your haggis tuber from Scotland. Beware French, or Romanian imitations.
Take a sharp knife - my aunt used her tongue, but I wouldn't recommend that on hygiene grounds - and cut cubes of the haggis tuber 5cm square.
Take an old cup and fill it with sheep dung. Water liberally. After a week dust the bottom (the cutting's, not yours) with a rooting hormone powder. Buy the best 'Robbie Burns' compost and plant the cuttings in the compost. Place them on a radiator so that they get bottom heat.
After ten days, your haggis cuttings should sprout little white fingers. Transfer them to your conservatory, if you haven't got a conservatory, a garage works fine. At the end of the December harvest them, and put them in a dark cupboard for about 3 weeks. On Burns day cut open your Haggis and fill with a lambs stomach, oats, deer liver and a chopped onion. The final secret ingredient is a leg - it's your leg which I have just pulled!
I hope you all enjoyed Robbie Burn's night.