I have a four-slot Black & Decker toaster (bought in Canada, but probably made in the USA) with a “Bagel” option: Press a button marked with a bagel, and it only toasts one side of whatever you put into it. My T-fal toaster in Moscow has no such option, so far as I remember (I haven’t seen it in over a year now).
I was once served one-sided toast at a restaurant in Moscow. It was owned by a Canadian, but that didn’t seem to matter. The cook, who really should have known better, blackened one side of the bread by holding it over a gas flame. I sent it back and told him to blacken the other side.
I don’t think I was ever served one-sided toast in the UK, but that may have been because they knew I was from the other side of the Atlantic.
Just to go back to the zombie. The song is about Quentin Crisp who was born in 1908 and in those days bread was toasted by putting it on a roasting fork and holding it in the fire and generally one side would get much more toasty than the other.
Ok, so the vague explanation (as far as I know) is this.
Electric toasters are not ubiquitous in the UK, I grew up without one, and even if I had one (there’s probably one in the junk room), I forget to use it.
We stick it under the grill, called a broiler in the US. We do one side in a couple of minutes, and another side can be optional. I’ve never skipped the second side. (*)
However, some tradition and simple cooking ways vary across the UK. Bread Rolls can go by many names in different regions. The way we do chips (fries to you) varies from town to town. So it is possible that some regions do do this, it wouldn’t surprise me to see someone in a shared holiday home do that.
(*) Watch a brit get served a Grilled Cheese Sandwich in the US. They expect the bread to be toasted dry, and see it to be what they’d call a “Fried Bread and Cheese sandwich”. Some won’t eat it due to it being too greasy.
