Combine the water and sugar in a small nonreactive saucepan. Bring to a boil, stirring occasionally to dissolve the sugar. Cool the syrup. Rinse the berries. Wrap and refrigerate a few attractive ones to garnish the granita. Hull and puree the remaining strawberries in a blender. Measure 2½ cups strawberry puree and add to the cooled syrup. Stir well to combine.
Pour the mixture into a nonreactive gratin dish or roasting pan and place in the freezer. When the mixture starts to freeze, stir it every 10 minutes, scraping the granita off the bottom and sides of the pan so that it freezes evenly. When the granita no longer has any unfrozen liquid in it, stir well and pack in a chilled container. Press plastic wrap against the surface, cover the container with a lid, and store in the freezer. The granita is best on the day it is made. Serve the granita in chilled stemmed glasses topped with a spoonful of unsweetened whipped cream. Garnish each portion with a whole berry.
If the granita freezes to a solid block, pop it out of the container, cut into thick slices with a stainless steel knife, and chop the slices finely. Replace in the container and freeze until serving time.
© 1990 Nick Malgieri. All rights reserved.