Grease a 27 cm fluted quiche dish Volume 1.5 L 3 1/2 cm deep In a blender, fitted with a blade attachment add the butter and the egg yolk and blend until incorporated
Add the flour, cornflour, mustard and salt and blend until it resembles fine breadcrumbs
Now add the iced water 1 tablespoon at a time and blitz until dough comes together
Tip the dough into the buttered quiche dish
Press the dough up the side walls of the quiche dish and on the base of the dish ensuring an even level of dough
Dock the pastry with a fork (prick)
Cover with plastic wrap and refrigerate for an hour or until needed
Preheat the oven to 200°C
Line the pastry case with baking paper
Top the baking paper with baking beads
Blind bake the pastry case for 20 minutes. Remove baking beads and leave to cool
Brush with egg white once cool
You pastry case is now ready to fill with your desired filling.
This pastry freezes well too.