Träipen, sometimes treipen, is the Luxembourg variant of black pudding. The sausages are traditionally prepared from a hog's head (or offal and any other scraps of pork), fat, rind and blood. Other ingredients may include green cabbage, onions, honey and spices such as caraway.
There are many variants to local recipes for its preparation but basically the meat and rind are boiled with salt, then minced and mixed with finely ground green cabbage. Fresh blood is added together with breadcrumbs and the mixture is put into intestine casings. The sausages are then boiled for 15 minutes in a large saucepan until cooked.
This article also draws on the Luxembourg Wikipedia article Traipen