Leftover meat can be frozen but do not keep it at room temperature for any longer than necessary. If the meat is still warm, put the plate in the refrigerator to cool quickly and then freeze it immediately so the bacteria that might cause food poisoning have no time to grow.
To freeze a leftover joint, carve the meat and pack the portions separately in foil or airtight plastic freezer bags, or cover the slices in gravy and store in freezer boxes. Freeze casseroles or curries in plastic boxes or bags. They will keep for up to two months. It is not advisable to refreeze meat that was frozen before being cooked as the texture suffers considerably.