In a mixing bowl, combine red onion, mayonnaise, sour cream, Swerve, apple cider vinegar, lemon juice, salt, and pepper.
Add coleslaw mix to the mixing bowl and thoroughly combine.
Cover and refrigerate for 1-2 hours before serving.
Notes
You can also use a small head of cabbage (shredded), one carrot (shredded), and about 1/2 cup shredded red cabbage. For the most nutritional accuracy, make sure the amount that you use weighs between 14 and 16 oz.