Rag pudding or rag pie is a traditional delicacy made by cooking a combination of ground beef and onions in a suet pastry. The whole concoction is cooked in cotton or muslin rags, hence the name. It is believed that rag pudding was invented in the 19th century in Oldham, as an easy way of making a small amount of meat go a long way, satiating the hungry mill worker's appetites with plenty of calories.