Shred 1 medium head green cabbage
Shred 1 medium carrot (optional)
Thinly slice 1 small red onion (optional)
In a bowl, whisk together 1/2 cup mayonnaise
Add 2 tablespoons apple cider vinegar
Add 1 tablespoon Dijon mustard
Add 1 to 2 tablespoons sugar (optional)
Add 1/2 teaspoon salt
Add 1/4 teaspoon black pepper
Pour dressing over cabbage mixture
Toss until evenly coated
Taste and adjust salt, pepper, vinegar, or sugar
Cover and refrigerate 30 minutes to 2 hours before serving
Serve chilled