Make the Basil Granita: Bring the water, lemon juice, sugar and a pinch of salt to a boil in a small saucepan over medium high heat, stirring occasionally. Remove from heat, set aside and allow to cool for 20 minutes. Add the basil and allow leaves to steep for 10 minutes. Use an immersion blender, or transfer mixture to a blender, and puree. Strain mixture into a container and place in the freezer. Allow mixture to freeze partially, this should take about 4-6 hours depending on your freezer. When mixture is partially frozen, scrape with a fork and place back in freezer. Continue to freeze, scrapping granite occasionally.
Form the Prosciutto Rosettes: Take one slice of prosciutto in your hand and roll (like a fruit roll up), turning out the tops to form rosettes. Set aside in the refrigerator until ready to use.
Plate the Salad: Arrange the tomato slices and red onion on each plate. Season with salt and pepper to taste. Drizzle with balsamic vinegar and top with torn burrata and a scoop of basil granite. Garnish with prosciutto rosettes.
Notes
*Inactive time of 10+ hours *For a less pungent red onion taste, soak onion slices in water for 20 minutes. Drain well. *Basil Granita can be made in advance and will keep in the freezer for up to one month. *For best presentation, place plates in the refrigerator for an hour, or more, before arranging salad. *Serve with crusty artisanal bread