1. soak the raisins in port wine. Peel the onions, cut them into thin slices, blanch them in salted water and drain them in a sieve. 2. Stir the red wine vinegar with the poultry stock and add the olive oil. Add the raisins with the port wine and the capers and season with salt, pepper and a pinch of sugar. Grind the coriander on top.
Mix the onions with the marinade, perhaps seasoning a little more. Serve lukewarm (e.g. with cold roast or pickled fish).
Our tip: Use high-quality red wine for a particularly fine taste!