I can’t agree with bubble and squeak which is a dish in itself. I’d also say that you can’t specify British sausage in an English breakfast as the Scots love slab/square/Lorne sausage. An English breakfast surely includes “link” sausage. But definitely you will need fried bread as well as toast, and black pudding too. It’s also extremely important that the mushrooms look and taste awful. If served by a lady who looks like she should be in Last of the Summer Wine you have gone balls deep !!!