Start by opening the coleslaw mix package and pouring it into a large mixing bowl. Next, finely chop the red cabbage and slice the green onions. Add both to the bowl with the coleslaw mix.
In a separate bowl, combine the mayonnaise, apple cider vinegar, Dijon mustard, salt, and pepper. Use a whisk to blend everything together until smooth and creamy.
Pour the dressing over the vegetable mixture in the large bowl. Using a spatula or spoon, gently toss everything together until the vegetables are well-coated with the dressing.
For the best flavor, cover the bowl and let the coleslaw chill in the refrigerator for at least 30 minutes. Once chilled, give it another quick toss and serve!
