I was planning to make a watermelon sorbet all along (using a blender after flesh was frozen) but when I cut it in half, I thought, "why can't I just freeze it like this then serve?" Scooping out its frozen flesh, it worked great as a granita.
So that's exactly what I tried. And it worked out great. I couldn't believe how easy it was.
No need for the rosewater but I love the flavor it adds. You can also make rose water if you have rose petals and an hour.
Rosewater Watermelon Granita
1 Personal size, seedless watermelon
Couple Tablespoons rose water
Slice personal-size, seedless watermelon in half. Freeze overnight or at least 8 hours. Take out and thaw for 30 minutes. Using ice cream scoop or sturdy spoon, scrape out flesh and drizzle with a tablespoon of rose water. Serve with mint, basil, or berries.
If you prefer to buy rosewater, amazon sells it: Heritage Flower Water Rose 8 oz Liquid