Skordalia (Σκορδαλιά) is not a sandwich and should not be read as one. It is a thick, emulsified garlic sauce, built on a base of either boiled potato or soaked stale bread, beaten with raw garlic, olive oil, and vinegar until it holds as a dense paste. It is national, eaten cold, and its usual home is the table rather than the bread case: classically alongside fried salt cod, beetroot, fried vegetables, or boiled greens. Its relevance to a sandwich catalog is narrow but real, which is that it occasionally crosses over as a spread, and that crossover is documented separately as the condiment record. This entry is about the sauce on its own terms.
The making is where it stands or falls. Garlic is crushed to a paste, often with salt as an abrasive. The base, potato riced or pressed while still warm, or stale bread soaked and squeezed nearly dry, is worked together with the garlic. Olive oil is then added gradually while beating, the way you build an emulsion, with vinegar going in to sharpen and loosen. Good execution means a smooth, stiff, spreadable paste with an aggressive but clean garlic hit and oil that is fully incorporated rather than weeping. Sloppy execution is a base worked until it turns gluey and elastic, especially with potato beaten too hard; oil added too fast so it splits and beads; too little acid so it sits heavy and flat; or so much raw garlic it is simply harsh rather than pungent. The texture failure with overworked potato is the most common and the least recoverable.
It shifts mostly with the base and what is beaten in. The potato version is denser and milder; the bread version is lighter and tangier and takes acid better. Walnuts or almonds are a frequent addition, ground in for body and a slightly bitter depth. Consistency is a regional and household preference, from a firm scoopable paste to something nearly pourable. Its specific behavior as a sandwich spread, where its garlic punch and emulsified body do useful work against fried or fatty fillings, is treated in the separate condiment record and deserves its own article rather than being crowded in here. Read on its own, Skordalia is a garlic emulsion judged like any emulsion: by its texture, its balance of oil and acid, and whether the garlic reads as sharp depth or just heat.