Preheat the oven to 180'C.
Scrape the seeds from the vanilla pod, cut the butter into small cubes and place in a bowl. Add the flour and the sugar and rub together with the tips of your fingers until the mixture resembles breadcrumbs. Add the egg and bring the mix together until it forms a ball. Knead with the palm of your hand until smooth, wrap in cling film and rest in the fridge for at least 30 minutes.
Roll the pastry out between 2 sheets of baking paper to 5mm thick. Grease the inside of the tart cases with soft butter and dust with plain flour.
Transfer the pastry to the tart case and trim the edges. Line the inside of the tart with baking parchment and cover with baking beans. Transfer to the oven and blind bake for 15 minutes until edges are golden brown. Remove the baking beans and continue to cook until the tart looks even in colour.
Remove from the oven and allow to cool.
To make the ganache, bring the cream to a rising boil.
Remove from the heat and add the chocolate.
Let stand for 2 minutes before stirring to a smooth consistency then stir in the liqueur.
Pour the mixture into the cooled tart case and allow to stand at room temperature until the ganache has set.
Serve with a dollop of clotted cream.
«Vary the flavours in the tart by replacing the liqueur with any other liquid that you think would go with chocolate.»