Combine sugar and cornflour in the top of a double saucepan. Stir in milk and cook over direct heat, stirring all the time, until mixture comes to a boil. Boil for 1 minute. Beat yolks slightly, add a little hot milk mixture and pour back into milk and sugar mixture, stirring. Cook, stirring, over hot but not boiling water, until thickened (5 to 10 minutes). Strain and cool. Add vanilla extract and Kirsch; cover with waxed paper and refrigerate until well chilled.
Peel and core pears. Dissolve sugar in wine with lemon rind, cloves and ginger. Bring to a boil and cook for 3 minutes. Reduce heat to simmering point, stir in red food colouring and poach pears very gently, turning occasionally, until tender but not mushy. Remove from syrup and cool.
Soak gelatine in cold water and add with lemon juice and apple purée to the hot syrup. Mix thoroughly until smooth; cool.
Half-fill flan case with Pastry Cream; re-form pears and arrange on pastry base. Cover pears with red apple-wine sauce.