01 - In a large mixing bowl, mix green cabbage, red cabbage if using, grated carrots, and sliced green onions.
02 - In a small bowl, whisk together mayonnaise, sour cream, apple cider vinegar, Dijon mustard, honey or sugar, celery seed, salt, and pepper until smooth.
03 - Pour the dressing over the vegetable mixture and toss thoroughly to coat evenly.
04 - Taste the coleslaw and modify salt and pepper as preferred.
05 - Cover the bowl and refrigerate for at least 30 minutes to allow flavors to develop.