According to this graphic, all 9 groups would consider a McDonalds cheeseburger to be a sandwich, even the "hardline traditionalists": "A sandwich must have a classic sandwich shape: two pieces of bread/baked product, with toppings in between; must have classic sandwich toppings: meat, cheese, lettuce, condiments, etc."
Clearly there's an entire missing dimension to the graphic, because it totally denies the existence of the Hamburger Irredentist Youth League to which OJFord belongs!
I don't think I'm saying anything contrary or unusual for UK. The top left three (structure and ingredients pure/neutral, but not both neutral /hotdog) as pictured I would consider sandwiches.
But I think temperature is a better indicator than ingredients: 'a sandwich' is not cooked (it's ingredients might be, like meat obviously, but then cooled) or hot.
Of course you can have a 'toasted sandwich', but the qualifier's important, it's basically a different thing that happens to share a word - if you ordered a 'cheese sandwich' and it came out toasted you'd be surprised.
Which makes a hotdog trivially not a sandwich, but you could slice up some sausages the next day and have them between slices of buttered bread for a 'sausage sandwich' (which likewise is not a term anyone would use for a hotdog!)
In the US, toasted and hot "sandwiches" are commonplace. At Subway (the fast-food franchise with the largest number of franchises) the process for making many of their "sandwiches" routinely involves toasting them during the preparation process, notably the sweet onion chicken teriyaki. Similarly, a "club sandwich" has obligatorily toasted bread, although it also includes cold ingredients, and a Philly cheesesteak sandwich is always hot, as is a French dip, any other kind of roast beef sandwich, or a grilled cheese sandwich.
I'm curious if these "foods" exist in the UK, and if so, what they're called!
Clearly there's an entire missing dimension to the graphic, because it totally denies the existence of the Hamburger Irredentist Youth League to which OJFord belongs!