Preheat the oven to 180°C. Place all the ingredients for the pastry into a Compact Food Processor with the Knife Blade attachment and blitz them to a smooth dough. Press the dough into the base and up the sides of 6 tart tins (10cm diameter). Place in the oven for 8-12 minutes, or until set and golden. Leave to cool.
Chop the chocolate and butter into 1cm cubes, then add them into a large mixing bowl. Add the cream to a small saucepan and heat to a boil. As soon as it starts to rise up, pour it over the chocolate and butter and leave it to melt for a minute before stirring to combine everything. Pour it into the cooked pastry bases and transfer to the fridge to cool while you make the cherry filling.
Destone the cherries and add them into a medium saucepan. Squeeze in the juice of the lemon and add the sugar. Bring it to a boil and simmer for 15 minutes, or until it is syrupy and the cherries have broken down.
Dissolve the cornflour in enough water to allow it to dissolve fully (around 50-75ml), then add it into the cherry mixture and stir to combine. Cook it for a minute until very thick, then remove from the heat and leave to cool slightly before spooning it over the ganache. Transfer the pies back to the fridge and chill for an hour before serving. Makes 6 small pies.