Reminds me of potato salad.
Place cauliflower into a microwave-safe bowl, cover, and cook in microwave oven until tender, about 7 minutes. Uncover and cool for 5 minutes.
Stir eggs, creamy salad dressing, celery, green onions, sour cream, apple cider vinegar, sugar, salt, and black pepper in a bowl until thoroughly combined. Mix cauliflower into dressing. Chill at least 1 hour before serving.
Per Serving: 236 calories; protein 7.5g; carbohydrates 15.4g; fat 16.4g; cholesterol 158.9mg; sodium 460.1mg.