Shortbread Blackcurrant Tartlets

Preheat the oven to 180°C (350°F) and lightly grease the tartlet tins.
In a mixing bowl, combine the flour, butter, and icing sugar.
Use your fingertips to rub the butter into the flour until the mixture resembles breadcrumbs.
Add the egg yolk and vanilla extract, and mix to form a dough.
Wrap in cling film and chill in the fridge for 30 minutes.
Once chilled, roll out the dough on a floured surface to about 3mm thick.
Cut out circles to fit your tartlet tins and press the dough into the tins.
Prick the base of each tart with a fork and bake in the preheated oven for 10-12 minutes, or until lightly golden.
While the crusts are cooling, prepare the blackcurrant filling.
Place the blackcurrants, sugar, and lemon juice in a saucepan over medium heat.
In a small bowl, mix the cornflour with water to make a slurry.
Once the blackcurrants are soft and have released their juice, stir in the cornflour mixture.
Cook for another 2-3 minutes until the filling thickens, then remove from heat and let it cool slightly.
Once the tart shells have cooled, spoon the blackcurrant filling into each tartlet shell.
Chill the tartlets in the fridge for at least 1 hour before serving.