01 - In a large mixing bowl, combine finely shredded green cabbage, red cabbage, julienned carrots, and sliced green onions.
02 - In a separate small bowl, whisk together mayonnaise, sour cream, apple cider vinegar, Dijon mustard, honey, celery seed if using, salt, and freshly ground black pepper until smooth and well incorporated.
03 - Pour the dressing over the vegetable mixture and toss thoroughly until evenly coated.
04 - Cover the bowl and refrigerate for at least 30 minutes to allow flavors to develop.
05 - Give the coleslaw a final toss, adjust seasoning if necessary, and serve chilled.