The coastal fish sandwich is shaped by how little it should do. A piece of shellfish or oily fish at its best needs almost nothing, so the build is a deliberate exercise in restraint: good bread, butter or a light bound sauce, an acid note, and the catch. The temptation is to dress it up; the discipline is to get out of its way and let a Cromer crab or a Morecambe shrimp be the whole sandwich.
The craft is freshness and balance. Crab is picked and lightly bound so it holds without turning to paste; prawns are folded into a Marie Rose sauce sharp enough to cut their sweetness; kipper and mackerel, oily and strong, are matched to bread and butter and a squeeze of lemon the way they are matched to a glass of something cold. The bread is plain and the sauce is minimal because the fish carries the flavour on its own and a heavy dressing only masks it.
The variations follow the shoreline. The dressed crab sandwich, the prawn cocktail and prawn mayo, the lobster and crayfish builds, the cockle and whelk and jellied eel of the working coast, the smoked haddock and gravlax of the colder water: each is the same idea met in a different catch. Each deserves its own article rather than being crowded in here.