Mix all salad ingredients. You can do this earlier so the flavors combine. If we're making the salad for a dish that already has dried plums, we don't add them to the cabbage.
The cabbage must be very thinly shredded (thinner than in the photo), preferably with a mandoline or a special vegetable grater. If you want the cabbage to be less crispy but softer (purple cabbage), you can blanch it first: shred it, place in a pot, pour boiling water over it, season with salt and 1 tablespoon sugar, bring to a boil, then simmer for about 2-3 minutes. Finally add 1-2 tablespoons of vinegar to restore the original color of the cabbage. Drain and cool, then proceed as above, which means combine with the rest of the salad ingredients.