Yummy Chicken Walnut Summer Salad

Name: Yummy Chicken Walnut Summer Salad
Prep time: 10 min
Cook time: 30 min
Total time: 40 min
Cuisine: American
Ingredients: 2 medium chicken breast (skinless); 2 stalks celery (finely chopped); 1/4 cup onion (finely chopped); 1 bunch red grapes (sliced in half); 1 cup mayonnaise; 8 tablespoons whipped cream; 1 teaspoon white pepper