There was a tidy one by Canary Wharf, owner bred them bengal cats as I remember….not a window in the gaff ! lol
Then there was a decent one down Petticoat Lane, used to go in early before they started setting up the stalls for the day.
Georges (I think) at Canning Town (near Tate & Lyle)
Also, out of town, there was a great cafe at Brighton Fruit & Veg market (I suppose that’s long gone now?)…..they did a breakfast called the gut buster and you got a little prize if you could eat it.
Back of Borough Market had a good one, they used to cook liver really tough just