Wash and chop the broccoli and cauliflower into bite-sized pieces, finely slice the carrots, and dice the red onion. Combine all vegetables in a large mixing bowl with the sweet corn.

In a medium bowl, mix mayonnaise and sour cream until smooth. Stir in the dry ranch mix.

Grate the sharp cheddar cheese and fold into the vegetable mixture without crushing the vegetables.

Pour the dressing over the mixed vegetables and cheese. Gently fold until evenly coated.

Cover the bowl with plastic wrap and refrigerate for at least 30 minutes to allow flavors to meld.