In a large mixing bowl combine mayonnaise, dijon mustard, salt, pepper, and apple cider vinegar and mix thoroughly
Add coleslaw mix and chopped parsley to the bowl
Mix to combine all of the ingredients into an even mixture
Place in the fridge to chill for at least an hour prior to enjoying - I find that the longer coleslaw sits, the better it tastes so I like to prepare mine at least 12 hours ahead of eating