Storage & ReheatingTo store, place the casserole in the fridge for up to 5 days or in the freezer for up to 6 months, both in an airtight container. Allow to thaw in the fridge overnight before reheating from frozen. To reheat, place the casserole into a pot over medium-high heat and bring the sauce to a simmer. Once simmering, cover with a lid and let it continue to simmer for 10 minutes, ensuring the beef is hot throughout. Alternatively, reheat in the microwave in bursts, mixing between each one.