6 cups watermelon seedless (or seeded if you must) OR one tiny watermelon
1/2 cup sugar (to taste)
juice of a lemon
Blend the watermelon in your blender until it reaches a very smooth consistency. Pour into a glass bowl. Mix in the sugar and lemon until sugar dissolves completely. Place in the freezer and set the timer for 30 minutes. Every thirty minutes for four hours or so, scrape the top and sides of the mixture to distribute the forming ice crystals. When it's just past the slushy stage. Serve in little glass dishes or cups. A lemon twist is a nice garnish. If you leave it in the freezer overnight, you can always take it out for about 30 minutes and crush it back to granita stage.
I believe I should give Emeril Lagasse credit for this recipe. My recollection is that it came from the book jacket of his fabulous kids cookbook, EMERIL'S THERE'S A CHEF IN MY FAMILY. My youngest prepares his Fettucini Alfredo to our great delight!