Definition: Black pudding is not a pudding but actually a sausage made from pigs' blood, onions, herbs, spices, oatmeal or barley.Black Pudding, or Blood pudding is sliced and fried and an intrinsic part of a Full Breakfast. Also Known As: blood pudding, in Ireland is also called drisheen.efinition: Black pudding is not a pudding but actually a sausage made from pigs' blood, onions, herbs, spices, oatmeal or barley.