For me its ketchup on chip shop fish and chips and Hot Dogs (accompanied by mustard) only. This sickly sweet mush has no business being anywhere else other than with chip shop fish and chips – unless, of course, you treat yourself to having your Fish and Chips with Gravy or curry sauce, which supersedes the need for Ketchup.
Mayo on chips if not chip shop fish and chips. But of course its brown sauce on bacon and sausage butty’s or a fry up. On eggs or an omelette there has to be a generous sprinkling of Hot Smoked Paprika!
Obviously Gravy is the king of sauces so I wouldn’t sully my plate with ketchup or brown sauce if there is gravy on there. The only thing that can accompany gravy is mustard, horseradish sauce or mint sauce depending upon the meat! And certainly no sauces with a decent pie – there should be sufficient gravy/sauce within the pie. Assuming of course its a proper pie – i.e. with the filling completely contained with a short crust pastry or suet casing – no puff pastry and certainly no casserole with a puff pastry top masquerading as a Pie – the trade descriptions people need to get involved on this issue!