Preparation Combine first 6 ingredients in medium bowl. Mix in bitters, if desired. Pour mixture into 15x10x1-inch baking sheet. Freeze until icy at edges of sheet, about 25 minutes. Whisk to distribute frozen portions evenly. Freeze again until mixture is icy at edges of sheet and overall texture is slushy (for beverage), about 25 minutes longer. Then freeze until mixture is solid (for granita), about 45 minutes. Use fork to scrape granita into icy flakes. Cover and freeze at least 1 hour and up to 2 days. Scoop granita into goblets. Garnish with fruit and mint and serve.
Preparation Combine first 6 ingredients in medium bowl. Mix in bitters, if desired. Pour mixture into 15x10x1-inch baking sheet. Freeze until icy at edges of sheet, about 25 minutes. Whisk to distribute frozen portions evenly. Freeze again until mixture is icy at edges of sheet and overall texture is slushy (for beverage), about 25 minutes longer. Then freeze until mixture is solid (for granita), about 45 minutes. Use fork to scrape granita into icy flakes. Cover and freeze at least 1 hour and up to 2 days. Scoop granita into goblets. Garnish with fruit and mint and serve.