Rub the flour, salt, and butter together until the mixture resembles breadcrumbs.
Add water gradually to form a dough, then knead lightly and chill for 30 minutes.
Preheat the oven to 180°C.
Roll the pastry to 5mm thickness and cut four 15cm circles and four 10cm circles.
Line four dariole moulds with the larger pastry circles.
Mix blueberries, sugar, and vanilla seeds, then divide and press the mixture into the moulds.
Seal the pies with the smaller pastry circles using beaten egg yolk and crimp the edges.
Bake the pies for 30 to 35 minutes until golden-brown.
Cool the pies for five minutes before removing them from the moulds.
Whisk egg yolks and sugar together for the custard.
Boil milk and cream, whisk into the eggs, then heat slowly until the custard thickens.
Cook the compote blueberries, sugar, and water in a hot pan for 3 minutes until syrupy.
Serve the pie on a pool of custard with drizzled compote and clotted cream.