This is one of my favorite treats I learned to make in Italy it can be described in three words: simple, sweet, delicious,(and cheap).
You will need:
1 watermelon(cubed & frozen)
All you have to do is place the frozen watermelon cubes in the blender on high for about 2 minutes or until a sorbet consistency.
As I said simple, sweet, and if you try it I'm sure you will find delicious. Enjoy!