Wash, hull, and slice the strawberries. Place sliced strawberries in a large bowl. Toss the strawberries with the sugar; let stand for at least one hour at room temperature, or up to four hours. The strawberries will be very juicy.
Puree the strawberries and their juices with the water in a blender. Taste and add fresh lemon juice, if desired. At this point, if you want, strain out any seeds.
Pour strawberry mixture into a 13x9-inch baking dish. Cover tightly with plastic wrap and freeze approximately 45 minutes or until icy at edge of pan.
After 45 minutes, whisk to distribute frozen portions evenly. Cover and freeze again until icy at edge of pan and overall texture is slushy (be sure to scrape the ice crystals off the sides and into the middle of the pan) about 45 minutes.
After 45 minutes, again whisk to distribute frozen portions evenly. Cover and return to freezer and freeze about 3 hours or overnight until frozen solid.
When ready to serve the granita, remove from freezer. Using a fork, scrape granita down length of pan, forming icy flakes. Return to freezer for at least 1 hour. Can be made 1 day ahead. When served, the granita should look like a fluffy pile of dry red crystals.
To serve, scoop flaked granita into tall goblets or parfait glasses. If the granita is too solid you can allow it to sit in the refrigerator for half an hour until you can scrape it with a fork. Garnish with mint leaves, and serve immediately with iced tea spoons.
Granita looks fantastic if served in wine or martini glasses. Moisten rims of 6 martini or wine glasses with water; dip rims into some sugar, and then add the granita.
For an extra-special taste sensation, drizzle the tops (for use a dropper) of each serving of Strawberry Granita with aged-balsamic vinegar. So good!
Makes 6 servings.