Chilled Blackberry Snow

Ingredients

 * blackberries - 450 g, (1 lb), fresh or frozen, thawed,
 * egg whites - 2,
 * caster sugar - 50 g (2 oz),
 * double cream - 300 ml.

Directions
1. Purée the blackberries and rub through a nylon sieve. Pour the purée into a rigid container and freeze for about 2 hours.

2. Whisk the egg whites until stiff, then add the Sugar gradually, whisking until the mixture stands in soft peaks. Whip the cream until it just holds its shape.

3. Remove the frozen blackberry purée from the freezer and mash to break down any large ice crystals, being careful not to break it down completely.

4. Fold the cream and egg whites together, then quickly fold in the semi-frozen blackberry puree to form a swirled effect. Spoon into tall glasses and serve immediately.