Haggis is marvellous stuff. Who would have thought of mincing sheep offal, mixing it with oats and stuffing it into a sheep's stomach? It's kind of bizarre, but also totally delicious. For most people, haggis means Burn's Night, which happens on the 25th January. But there's no reason why you shouldn't eat it all year round, and you can also use it in scotch eggs, lasagne, sausages etc.
The consumption of lungs is banned in the US, but you could substitute some lamb meat for that. If you can't obtain a stomach, you can use sausage casing instead - it's only there to hold the filling together while it cooks.
If you are using a stomach, turn it inside out and rinse with boiling water. Leave to soak in water overnight. If you are using sausage casings, soak them in cold water for at least an hour.
Peel and finely chop the onion. When the offal is cooked, remove it from the pan (but keep the cooking water), chop it into large chunks and pass it through a mincer using the coarse plate. Alternatively you could whizz it in a food processor, but be careful you maintain a crumbly texture rather than a mush.
Boil the haggis or sausages in plenty of water for 2-3 hours.
The quantity of oats should be half the weight of the meat.