Taramosalata (Ταραμοσαλάτα) is a fish-roe dip, not a sandwich, and this entry treats it honestly as what it is: an emulsified spread of cured roe, bread or potato, oil and lemon, eaten as part of a meze table or smeared on bread. It is national, served cold, and its role on bread is that of a condiment or a simple open-faced bite rather than the core of a built sandwich. Judging it means judging a sauce, not a filling, so the questions are about texture, balance and what it does to the bread under it.
The make is an emulsion and the order is the craft. Cured fish roe, tarama, is the base; it is loosened, then either soaked stale bread or boiled potato is worked in to give body, and oil is beaten in slowly while lemon juice cuts and brightens. Done right the result is pale, light and fluffy, glossy from the oil but not greasy, with the roe present as a clean saline note rather than a harsh fishy slap. As something to eat on bread, a thin even spread on a sturdy crusty slice or a piece of toasted pita is the working format; the bread needs enough structure to carry the rich paste without going slack. Good execution is a smooth, airy emulsion, salt and lemon in balance, the roe tasting clean; sloppy execution is a broken oily mass, a paste so salty or fishy it overwhelms anything near it, or a spread laid on too wet so it soaks soft bread to paste, the most common failure when it is used on bread at all.
How it shifts is mostly the base and the color. A bread-thickened taramosalata is softer and milder; a potato-based one is denser and holds a spread better. Quantity of roe drives intensity, and the brightest versions lean harder on lemon to keep the richness in check. On a meze spread it sits beside tzatziki, olives and other dips and is scooped, not spread thick; as a bread topping it works best as a thin sharp accent under or beside other things rather than a thick standalone layer. The wider world of Greek cold dips and the meze table it belongs to is its own large subject and deserves its own article rather than being crowded in here. The test is simple: a stable airy emulsion, clean balanced roe, and a thin layer on bread firm enough to take it.