There are several ways to reheat gravy: Reheating in a saucepan - You can reheat whiskey sauce by gently reheating the sauce in a saucepan while stirring. Add a little extra liquid if needed (water or plant cream) as the sauce may thicken when reheated.  Reheating in a microwave - place the sauce in a microwave-safe bowl and add a little extra water or plant milk. Cover with a microwave-safe lid and reheat the sauce in the microwave for 2-3 minutes depending on how much sauce you’re reheating. Stir the sauce before serving to combine everything and make the sauce creamy.