Cook the stains in salted water until they are al dente.
In the meantime, heat the oil, add sugar and let it caramelize. Stir in the onions, fry them briefly and add the white cabbage with the caraway seeds. Roast the white cabbage brown, this will improve the taste.
Deglaze with vinegar and broth, season with salt, pepper and simmer on a low heat for about 30 minutes. Add the drained stains and let them get hot. Season to taste with salt and pepper before serving.