Boil the potatoes, let them cool down a bit, peel them and cut them into slices. Mix the broth with the vinegar and horseradish and pour over the potatoes. Fry the onions and bacon in the oil in a pan, leave to cool and add to the potatoes. Mix everything carefully and season with salt, pepper and sugar.
Cut the endive salad into strips and fold in just before serving.
If you`d rather mix cucumber in the salad, you can add it earlier.