You can swap out chicken breasts for thighs for a richer flavor. Feel free to use homemade gravy if you prefer. Add vegetables like carrots or peas to the slow cooker for a more hearty meal, or try different types of gravy mix like onion or mushroom for a twist. Leftovers can be stored in an airtight container in the fridge for up to 3 days. Reheat on the stovetop or in the microwave, adding a splash of broth if needed to keep it moist.