An authentic full English breakfast requires specific traditional components cooked together on a flat top, including bubble and squeak, bangers, back bacon, black pudding, Heinz beans, mushrooms, tomatoes, fried eggs, and buttered toast.
The full English breakfast is a substantial cooked meal often served in Britain and Ireland, also referred to as a full English, full Scottish, full Welsh, full Irish or Ulster fry depending on the region. A common traditional English breakfast typically includes back bacon, sausages (usually pork), eggs (fried, poached or scrambled), fried or grilled tomatoes, fried mushrooms, black pudding, baked beans, and toast or fried bread. Bubble and squeak is a traditional accompaniment but is now more commonly replaced by hash browns.
Bubble and squeak is an English dish made from cooked potatoes and cabbage, mixed together and fried, with its name alluding to the sounds made by the ingredients when being fried. The dish dates back to the early 1800s and was designed to use up leftovers, usually from a Sunday roast or Christmas dinner, originally combining leftover cooked potatoes and vegetables mashed up together then fried. Bangers are the quintessential British breakfast sausage, immortalized in classics like bangers and mash, though the term can refer to any British sausage. British sausages being called bangers seems to be a historical legacy from wartime when sausages sometimes exploded in the pan when cooked, with the slang name emerging during the first World War.
British back bacon is a combination of both pork belly and pork loin in one cut—the rounded lean bit on a rasher (slice) is the pork loin and the fatty streaky bit attached to it is the pork belly, creating an irresistible bacon eating experience honed into perfection over centuries by tradition. Black pudding is a type of blood sausage originating in the United Kingdom and Ireland, made from pork or occasionally beef blood, with pork fat or beef suet, and a cereal (usually oatmeal, oat groats, or barley groats), with the high proportion of cereal and use of certain herbs like pennyroyal distinguishing it from other blood sausages. The integration of baked beans into the English breakfast is attributed to a marketing campaign by the Heinz company in 1927, promoting baked beans on toast as a good addition to the full English breakfast. Heinz beans are mentioned specifically in comments as essential, with people saying they can tell the difference from other brands.
A proper full English breakfast requires nine traditional components cooked together on a flat top, from bubble and squeak to back bacon.