Cheese and Branston is a plain Cheddar sandwich with one decision made for it, and that decision is the pickle. Branston is a dark, chunky, sweet-sharp pickle of vegetables and dates in a thick brown malt-vinegar sauce, and dropping a layer of it against the cheese is what turns the baseline cheese sandwich into a thing with its own name. The pickle is not a condiment painted thin for seasoning. It is a structural layer with as much volume and intent as the cheese it sits against, and the sandwich is built around the meeting of the two.
The craft is the contrast and the containment. Cheddar is fatty, dense, and one-note on its own; the pickle answers it with acidity, sugar, and a soft jammy texture full of vegetable chunks that break the uniformity of the cheese. The catch is moisture. Branston is wet and acidic, so it will soak straight into a slice given the chance, and the fix is the same fix the cheese shelf always uses: butter spread to the edges to waterproof the crumb, with the cheese itself laid as a solid slab against the bread to act as a second wall between the pickle and the slice. The cheese is cut thick so it holds its own against an assertive pickle rather than being overwhelmed by it. Soft white or a sturdy plain bread carries the load, pressed just enough to bind without forcing the pickle out the sides.
The pickle slot is where this sandwich's relatives live. A milder fruit chutney softens the sharpness toward sweet; piccalilli pushes the mustard and the crunch much harder; an onion slice trades the jar for raw pungency. Each deserves its own article rather than being crowded in here.