Ingredients

• 2 tablespoons chopped peeled fresh ginger
• 1/2 cup superfine granulated sugar
• 3/4 pounds blueberries (2 1/2 cups), thawed if frozen
• 3/4 cup water
• 2 teaspoons fresh lime juice

Instructions

1. Finely grind ginger with sugar in a food processor. Add blueberries and purée until smooth. Force purée through a fine sieve into an 8- to 9-inch baking pan, pressing hard on solids (discard solids). Stir in water and lime juice.
2. Freeze, stirring and crushing lumps with a fork every hour, until evenly frozen, about 4 hours total. Scrape with a fork to lighten texture, crushing any lumps.
3. Serve immediately or freeze, covered, up to 3 days (rescrape to lighten texture again if necessary).