1. Combine all veggies in a large bowl or a large sealable plastic bag if preparing ahead.
2. Refrigerate until chilled.
3. Include red cabbage only if the slaw will be served within a couple hours of adding dressing; if the slaw with red cabbage is stored overnight, everything turns an ugly pink!
4. It still tastes good, though!
5. Dressing: In a small bowl, whisk together the mayonnaise and yogurt until smooth.
6. Add vinegars, mustard, and dry spices.
7. Whisk thoroughly to blend, set aside for 15-20 minutes or more for flavors to meld.
8. While whisking rapidly, slowly add the olive oil a few drops at a time.
9. Continue whisking until dressing is blended and emulsified.
10. For a real crispy slaw, toss dressing with veggies 5-15 minutes before serving.
11. For softer textured, but still crisp slaw, toss dressing with veggies 1-2 hours before serving and refrigerate until needed.
12. In either case, toss again to redistribute the dressing immediately before serving.
13. Slaw still tastes good after being stored in the refrigerator, it just gets softer.