1. Line a loaf tin with a double layer of cling film and then make the strawberry sauce. In a food processor or blender, whiz the strawberries with the lemon juice and icing sugar, then pour the mixture through a sieve into a bowl and discard the seeds left in the sieve.
2. Pour the cream into another bowl and whisk into soft peaks, then whisk through the cold custard and the vanilla extract
3. Crumble the meringue into the whipped cream and stir together to mix.
4. Add the strawberry sauce, swirling it through the cream and meringue mixture. Tip the mixture into the lined cake tin and smooth the surface with a spatula. Wrap the tin in cling film and freeze for at least eight hours or preferably overnight.
5. Take the frozen cake from the freezer and carefully left it out of the tin, turning it upside down on a serving plate or board. Cut into slices to serve either, on its own, with fresh strawberries or drizzled with warm chocolate sauce.