blended watermelon - as another flavour, but remove the seeds if any!
To make ice cream without ending up with a rock you need either an ice cream machine that churns the liquid or the lo-fi version in which you put the liquid in a plastic box and into the freezer. Then you give it a good shake every now and then so big chunks of ice don’t form. I’ve done this and it kinda works… but the machine is better
Also, the more fat and sugar the less “rock”…