• 450 g/1 lb cooking apples
• 450 g/1 lb blackberries
• 1.5 dl/¼ pint water
• 100 g/4 oz castor sugar
• juice of 1 lemon
• 15 g/½ oz powdered gelatine
• 2 egg whites

Peel and core the apples and slice into a saucepan. Add the washed blackberries, the water and 75 g (3 oz) of the sugar. Cover with a lid and simmer for about 15 minutes until the fruit is quite tender. Meanwhile, strain the lemon juice into a small basin, sprinkle in the gelatine and leave to soak.

When the fruit is cooked, draw off the heat. Add the soaked gelatine and stir until dissolved – the heat of the pan will be sufficient to do this. Rub the fruit and juice through a sieve into a mixing basin to make a purée; discard any pips from the blackberries remaining in the sieve. Set the fruit purée aside until cold and beginning to thicken.

Quickly whisk the egg whites until stiff, add the remaining sugar and beat again just to blend. Fold into the fruit purée, pour the mixture into a serving dish and chill until set firm.