Method

• 1.
  Place a 1-litre (4-cup) loaf pan in the freezer. Place 2 punnets (400g) blueberries, caster sugar and 2 cups (500ml) water in a pan over low heat and cook, stirring occasionally, for 10-12 minutes until sugar dissolves and blueberries are just beginning to break down. Add the mint and lime juice, then cool slightly.
• 2.
  Blend the blueberry mixture until smooth, then pass through a fine sieve and cool to room temperature.Pour into the chilled loaf pan, cover and freeze overnight.
• 3.
  Toss the remaining berries with icing sugar and limoncello, if using.
• 4.
  To serve, scrape granita with a spoon and layer in serving glasses with blueberries and extra mint.