Chop cabbage into chunks and run through your food processor, or chop fine. It's up to you to decide the size you'd like your cabbage to be.
Combine all of the dressing ingredients in a large bowl, whisk well.
Combine cabbage, carrots, and onion and toss well. Pour dressing over the slaw and turn to coat well.
Cover and refrigerate for at least 4 hours before serving to allow the cabbage to soak up the marinade. Overnight is best.
Fresh carrot should be grated fine, and if you don't want a pink tint to you slaw, squeeze out the excess moisture before combining it with the other slaw ingredients.
When you first make this KFC coleslaw, there will be an overwhelming flavor of cabbage. Do not despair! Allow the finished coleslaw to sit for at least 4 hours to allow the flavors to soak into the cabbage. Eating it too soon will result in a heavy cabbage flavor.
If you don't have buttermilk on hand, you can make your own. Add 1/2 teaspoon of lemon juice or white vinegar to 1/4 cup of milk to replace the buttermilk.
If you insist on using Miracle Whip to make this coleslaw instead of mayonnaise, be sure to reduce the sugar by half. I cannot guarantee your results as I have not made it with Miracle Whip and the flavor of each item is very different.