Found this on the net for you
1 sheep's lung (illegal in the U.S.; may be omitted if not available)
1 sheep's stomach
1 sheep heart
1 sheep liver
1/2 lb fresh suet (kidney leaf fat is preferred)
3/4 cup oatmeal (the ground type, NOT the Quaker Oats type!)
3 onions, finely chopped
1 teaspoon salt
1 teaspoon freshly ground pepper
1/2 teaspoon cayenne
1/2 teaspoon nutmeg
3/4 cup stock
I love them! I tend to bake them rather than boil them and serve them with a bit of whisky poured on top with mashed tatties and turnip. Yum!