Add mayo, sour cream, and lemon juice to a 1-cup measure and stir to blend.
Cut the chicken breasts each into 1/4-inch thick slices (should be around 3 1/2 cups of chicken strips). Add chicken, mozzarella, celery, green onions, tomatoes, parsley and cooked noodles into a large serving bowl and toss to blend.
Drizzle the mayo mixture over the chicken noodle mixture and toss to blend the dressing with the ingredients. Add salt and pepper to taste if desired. Cover and store in the refrigerator until right before it is being served.