Toss all veggies into a large bowl, ensuring the onions and scallions seperate and mix well with the cabbage and carrots. Cover with a moist paper towel and then plastic wrap and leave in the refrigerator until ready for service. Mix all dressing ingrediants in a medium bowl with a wisk, cover with plastic wrap, leaving dressing in refrigerator until ready for service. When ready for service, mix dressing again with a wisk, pour over veggies, toss and serve.