Trim the stalk end of the red cabbage and finely shred the cabbage. Cut the red onion in half and slice it thinly. Peel the beetroot and carrots and cut them both into thin matchsticks or grate coarsely. Halve the fennel bulb and shred it finely.
Put all the prepared vegetables, chopped parsley or dill and raisins or sultanas in a large salad bowl and toss them with your hands to combine well.
Make the dressing. Mix the yogurt with the vinegar, mustard, honey, crushed garlic, a pinch of salt and plenty of pepper. Pour this dressing over the slaw, mix well and leave to marinate for at least 1 hour. Serve the slaw with rye or sourdough bread.