The Orkney Cheddar sandwich is a cheese sandwich whose entire identity is locality. This is not generic block Cheddar but the island-made cheese of Orkney, off the north coast of Scotland, firm, close-textured, and sharper and more mineral than the soft mass-market versions, with a tang that comes from the milk and the place. The sandwich is that cheese cut thick on plain bread with butter underneath and one acid counter, and the defining fact is that the cheese is both the structure and the flavour. Swap in an anonymous Cheddar and it is a different, lesser sandwich; the point is that this particular island cheese is loud and specific enough to carry a build that does almost nothing else.
The craft is in the cut and the counter. A firm Cheddar like this is sliced thick enough to have presence in the bite but not so thick it dries the mouth and reads as a wall, and it is left in slices rather than grated so its texture stays part of the eating. Butter spread to the edges does two jobs: it bridges the salt and fat of the cheese to the wheat of the bread, and it waterproofs the crumb so a sharp pickle or chutney does not soak through and turn the base to paste before it is eaten. The bread is plain and soft on purpose, because a cheese this assertive needs no help and a strongly flavoured loaf would only argue with it. The acid, Branston, a sharp chutney, or pickled onion, is applied as a measured stripe to cut the richness without flooding it.
The variations are the rest of Britain's regional cheese shelf met with the same plain frame. Mature and vintage Cheddars push the sharpness further; the Isle of Mull and West Country Cheddars are the close island and regional cousins, each tasting of somewhere specific. Cheese and pickle, cheese and onion, and the ploughman's that sets a wedge against bread and chutney rather than slicing it all keep the same logic. A blue such as Stilton crumbled for distribution is the same idea with a different cheese. Each deserves its own article rather than being crowded in here.