This casserole can be varied by adding steamed broccoli, sautéed mushrooms, or frozen peas and carrots. For a spicy kick, add hot sauce or red pepper flakes. Other topping options include crushed potato chips, fried onions, or panko breadcrumbs. A 'Chef's Secret' suggests adding crumbled crispy bacon and fresh chives to the chicken mixture for a smoky, savory twist. Leftovers can be stored in the refrigerator for up to 4 days and reheated in the microwave or oven (350°F for 15-20 minutes) for best results.