In a large bowl, combine vinegar with Dijon mustard, oil, sugar, celery seeds, black pepper and salt. Add coleslaw mix well to coat. Cover bowl and place into the refrigerator for 30 minutes to 1 hour before using.
Add sliced green onion, thin strips of bell pepper or jalapenos to suit your needs. This recipe is simply a base, so get creative and make it your own.
Store leftover slaw in an air tight container in the refrigerator for up to 2 days after preparation.
*For vegan option, use a vegan friendly Dijon mustard.