The Sandwich Tarama is built around a spread, and the spread is the whole sandwich. Tarama is a cured fish-roe purée, the roe emulsified with bread or potato, oil, and lemon into a pale pink, dense, faintly briny cream that tastes of the sea and acid in equal measure. Spread thick on bread it does not behave like a filling that needs company; it behaves like the reason the bread is there. The build is a slice or split of bread, a generous layer of tarama, a squeeze of lemon, and the discipline to add almost nothing else.
The craft follows directly from what tarama is: rich, salty, intensely flavored, and soft. Because it is already an emulsion of roe and oil, it needs no butter and no second fat; pile a strong cheese or a sharp meat against it and you are fighting the roe instead of presenting it. The constraint it sets is the same one a good cured-fish spread always sets, lean on it and let one acidic note keep it honest. That note is lemon, sometimes a few rings of thin raw onion, sometimes a scatter of chopped chive or dill for definition, never enough to crowd the roe. The bread does the structural work the spread cannot, so it wants a real crust or a dense crumb rather than a soft loaf that goes slack under an oily layer. It is best cool, the tarama spread close to service and the lemon added late so the acid still cuts the salt rather than fading into it.
Variations move along the bread and the accents rather than the spread. On a crisp toasted slice it reads as an open-face tartine, the crunch set against the cream. Closed into a sandwich it wants the densest bread on the rack. A few rings of raw onion sharpen it; a film of fresh white cheese under the tarama softens the salt for a milder read; cucumber adds water and crunch against the density. The frame holds across all of them: a thick layer of cured roe spread, one bright acidic counter, a bread firm enough to carry an oily load. It belongs with the fish sandwiches the catalog groups under Baguette Poisson, and its specific contribution is the roe spread treated as the entire point, a sandwich whose job is to get a good bread under it and one squeeze of lemon over it.