Raspberry Gratin

Name: Raspberry Gratin
Yield: Serves 10
Cuisine: United Kingdom
Ingredients: 25 g/1 oz cornflour; 150 ml/¼ pint lemon juice; 1 packet powdered gelatine; 10 egg yolks, and 7 egg whites, size 2; 275 g/9 oz fresh raspberries icing sugar, for dusting; 350 g/12 oz caster sugar; 150 ml/¼ pint double cream