Mix the cocoa, sugar and cornflour in a saucepan and then gradually blend in the milk. Bring to the boil over a moderate heat, stirring continuously. Reduce the heat and continue stirring until thickened and smooth. Remove from the heat, stir in the vanilla extract and pour into 4 individual dishes. Cover with dampened greaseproof paper and allow to cool. Place in the refrigerator and chill for 2 hours.

Decorate with chocolate curls and strawberries.

To make the chocolate curls: Melt dark chocolate in a bowl over a saucepan of simmering water, spread onto a marble slab or laminated plastic surface. When dry to the touch, push a sharp knife across the surface of the chocolate to lift it into curls.