Remove the pulp from the watermelon removing all the seeds. Cut it into cubes, pour into a bowl and blend with the blender. Pour the mixture into a stainless steel pan and place all in pre-cooled blast chiller with the shock freezing function for 2 hours.
After the first 30 minutes begin to mix with the tines of the fork every 15-20 minutes in order to shell the mixture and obtain a granite. When the granita is ready, serve it with chocolate chips.