1. For the crème patissière base: heat the milk and cream in a heavy-based saucepan until almost boiling. Sift the flour and cornflour together. Beat the egg yolks and sugar together in a large bowl then mix in the flour. Add a splash of the hot creamy milk and whisk well until the mixture is smooth, then gradually whisk in the rest of the milk. Pour back into the pan and whisk over a medium-low heat for 3-5 minutes until thickened and smooth. Transfer to a bowl, cover and cool to room temperature, stirring occasionally to prevent a skin forming.
2. Quarter the strawberries and dust with icing sugar. Drizzle over the balsamic vinegar and toss to coat. Quickly cook the strawberries in a hot pan for 1minute until the strawberries just begin to break down. Spoon on to a plate and allow to cool.
3. Whip the double cream with a tablespoon of icing sugar to soft peak stage. Mix the whipped cream and crème patisserie together - the mixture should be two thirds cream to one third crème patisserie.
4. Layer the bottom of the glasses with some strawberries, scatter over some meringue then pipe over a little of the mixed cream. Repeat the layering as necessary and top with a spoonful of ice cream, a drizzle of sauce and a grating of chocolate. Garnish with a fan wafer and serve at once.