Cook cauliflower in boiling water to cover 10 minutes or until crisp-tender; drain.
Stir together soup, sour cream, and pepper in a large bowl. Stir in cauliflower, celery, onion, cheese, and, if desired, chicken. Spoon into a lightly greased 13- x 9-inch baking dish.
Sprinkle with potato chips.
Bake at 350 for 25 minutes.
Note: For testing purposes only, we used Ruffles Cheddar and Sour Cream Potato Chips.