I'm seriously concerned about the lack of mention of fried bread, doesn't count as a full English without the fried bread (fried in lard is best, but oil is allowed I suppose). Turning to other matters - egg fried, mushrooms yes but not the awful ones that come out of a can, tomatoes fried (canned are acceptable in this case), black pudding (not white), baked beans mandatory, bacon streaky and must be smoked. Hash brown is a modern import to be avoided if you want to stay authentic. On the side there should be a plate of toast or bread and butter (sliced white of course), and a mug of tea (coffee is permitted south of Warwick / Northampton). Best consumed in a café with a stinking hangover.