Bacon butty... Must use sliced bread, surely?

[ButteredRadishes]

Of the bacon is ina bread roll, it's a bacon roll, right?

Bacon butty, is between two slices of bread!

Yes?

No, OP! It's either a bap or a teacake, depending on your preference... at least where I grew up. All butties are served on such things, regardless of whether it's chips, meat slices or bacon. Throw in a bit of proper butter and your choice of filling and you're away!

Bacon butty is 2 slices of bread, at home and the butty shops.
However a bacon butty at the butty van is what they serve it you on (I kind of like the roulette of it) or at the chippy it comes on a barm.