4 cups chopped roasted skinless, boneless chicken breast (about 4 breasts)  | 
                                                1/4 cup chopped green onions  | 
                                                1/4 cup chopped red bell pepper  | 
                                                2 tablespoons finely chopped fresh flat-leaf parsley  | 
                                                1 (8-ounce) can sliced water chestnuts, drained and chopped  | 
                                                1/2 cup low-fat mayonnaise  | 
                                                1/4 cup reduced-fat sour cream  | 
                                                2 tablespoons fresh lemon juice  | 
                                                2 teaspoons dijon mustard  | 
                                                1/2 teaspoon salt  | 
                                                1/2 teaspoon freshly ground black pepper  | 
                                                cooking spray  | 
                                                3/4 cup (3 ounces) shredded swiss cheese  | 
                                                3/4 cup crushed baked potato chips (about 2 ounces)  |