Tell me about the "bacon butty" sandwich

I just found a brand of back bacon made here in the U.S. (Beeler’s), and I understand this is the kind you use to make an English “bacon butty”. Although I heard about them once, I’ve never seen or tasted this sandwich before.

I’d like to serve them tomorrow for lunch. What’s the best way to prepare them? Will a hamburger bun do? Should it be toasted? Should the back bacon be really crisp or should I leave it kind of chewy? Any info would be helpful.

Felicity Cloake in the Guardian had LOTS of opinions.

Good bacon is hard to find. I’m gonna think of you enjoying your bacon butty.

But from what I can tell it’s bacon on buttered white bread with catsup added. You can add literally anything else your heart desires.

I say a slice of avocado would be nice.

A bacon butty is several layers of bacon, covered in HP Sauce, on a soft, round, buttered bap.