Kartoffelsalat

Kartoffelsalat is German potato salad — and there are two of them. Which one arrives depends on where in the country you are, and people care about this more than outsiders expect.

What it actually is

Both versions start from waxy potatoes (festkochend), boiled in their skins, peeled and sliced while still warm so they drink up the dressing. After that they part ways.

In the north and west, the salad is bound with mayonnaise and studded with gherkins, onion and often egg, apple or ham. It is served cold.

In the south — Swabia and Bavaria above all — there is no mayonnaise at all. Warm slices are dressed with hot broth, vinegar, oil, mustard and onion, then left to stand. The potato starch does the work: the dressing turns creamy by itself. It is served lukewarm.

How it's served

• As a side, not a dish — with sausages, Schnitzel or Frikadellen.
• Lukewarm in the south, cold in the north.
• On Christmas Eve, with sausages — the traditional supper across much of Germany.

Writing it on a menu

• Say which style you make. This is the single most useful line: a Swabian guest served mayonnaise salad feels short-changed, and the reverse is just as true.
• Note the egg in the mayonnaise version; the southern one is naturally vegan if the broth is vegetable.
• Both are normally gluten-free — worth stating, since guests assume otherwise of a dressed salad.