Cut the papaya into chunks.
Put the papaya chunks in a freezer bag or container, seal and place in the freezer. The chunks need to freeze thoroughly, which takes about 2-3 hours (depending on the freezer).
Once the papaya chunks are frozen, remove from the freezer. Puree the chunks, adding a little water if necessary, until you have a smooth mixture. If you want to, you can add a little sugar to taste and puree again until smooth.
Serve immediately or store in an airtight container in the freezer (for up to two weeks).