Quarter the red cabbage, remove the outer withered leaves and cut out the stalk. Then grate or cut into very fine strips. Salt so that the salad draws juice.
Wash, quarter and core the apple. Cut the quarters into small pieces and add to the salad with the skin on. Peel the onion and cut into small cubes, also mix with the red cabbage. Add the lemon juice and extend with a little water. Now pepper the salad, pour a pinch of sugar and a good dash of oil over it. Mix the salad well and let it steep for 1 hour.
Variation: For a special kick, add tart cherry juice instead of water to lengthen it.
The salad tastes best if you prepare it a few hours in advance. But then it is no longer quite as crisp.