Osmosis causes water to be drawn from the cabbage when it is mixed with a dressing. To avoid this you can either: Store the chopped vegetables and dressing separately (for up to 3 days) and then mix just before serving. OR Salt the vegetables: Chop your vegetables as per the recipe, then toss well with 1 tsp of sea salt. Set aside for 20 minutes while you make the dressing. After the 20 minutes rinse the vegetables thoroughly in a colander under a running tap - you need to do this for 3-4 minutes to ensure the salt is washed away - then carefully dry the vegetables before combining them with the dressing.