Finely chop the green and red cabbage.
Shred the carrot and chop the green onions.
In a mixing bowl, combine the cabbage, carrot, and green onions.
In a separate bowl, mix together mayonnaise, lemon juice, Dijon mustard, and optional horseradish cream.
If desired, add keto maple syrup to the dressing.
Pour the dressing over the cabbage mixture and toss until well combined.
Adjust seasoning to taste, adding salt or pepper as needed.
Serve immediately or refrigerate for an hour to let the flavors meld.