Make the coleslaw dressing. In a medium bowl, whisk together the mayo, apple cider vinegar, mustard, maple syrup, celery seeds, salt, and several grinds of fresh pepper.
Make the coleslaw. In a large bowl, toss together the cabbage, carrots, and scallions. Pour the dressing over the top and toss to coat. Season to taste with more salt and pepper, as desired.
