Start  by preparing the chocolate pastry. Cream the margarine and sugar together then beat in the egg. Sieve the flour and cocoa and knead in the margarine mixture.

Line a 25 flan tin with the pastry and bake blind for 15 minutes. For the filling, chop the dark chocolate and melt over bain-marie. Remove from the heat, whisk in the caramel condensed milk, followed by the eggs. Pour mixture into the baked tart base and bake in the oven at 160°C for 20 minutes or until chocolate is set. Allow to cool down completely before serving.