In a large bowl, combine the thawed peas, diced cheddar cheese, chopped celery, chopped red bell pepper, and finely chopped red onion.
In a small bowl, whisk together the mayonnaise, sour cream, apple cider vinegar, sugar, salt, and black pepper until smooth and well combined.
Pour the dressing over the pea and vegetable mixture, gently tossing to coat all ingredients evenly.
Refrigerate for at least an hour before serving to allow the flavors to meld together.
Give the salad a gentle stir before serving. Enjoy!
