• To prepare the pastry, sift the flour, sugar and salt together into a large bowl.
• Cube the cold butter and add this to the sieved ingredients.
• Use your finger tips to crumble the butter into the flour until the mixture resembles fine bread crumbs.
• Crack the eggs into a glass and lightly beat with the vanilla extract.
• Make a well in the centre of the mixture and the eggs and vanilla mixture into the well.
• Using a swirling motion with your fingers, help the butter and flour mixture incorporate into the eggs. Slowly bringing more of the butter and flour mixture into the wet ingredients, continue doing this until a dough is formed. Do not overwork the dough.
• Once the dough is formed, cover in plastic wrap and allow to chill in the fridge for one hour.

The Filling

• Ensure you have trimmed the stalks off of the mulberries, and washed them well.
• Place the mulberries, castor sugar and lemon juice into a medium sized pan over medium to high heat.
• Allow the sugar to melt and the berries to start releasing their juices.
• Meanwhile combine the cornflour and water and stir to dissolve.
• Once the sugar has melted add the cornflour mixture to the mulberries and cook until the berries begin to thicken, this should take about 2 to 3 minutes.
• Remove from the heat and allow the mixture to cool to room temperature.
• Add the fresh uncooked blueberries to the cooled mulberry mixture and set aside.

Assembly

• Preheat the oven to 180°C
• Brush the tart tin with a little melted butter to ensure the pie doesn't stick.
• Remove the chilled pastry from the fridge and dust with flour on both sides.
• Roll out the pastry into a circular shape a little bigger than the size of your pie/ tart tin. Ensure that it has even thickness of about 3mm throughout.
• With the aid of your rolling pin, lift the pastry into the tart tin and use your finger tips to lightly press into shape.
• Place the pastry lined tart tin in the fridge while you prepare the lattice top.
• With the remainder of your pastry dough measure out strips for your lattice of about 2cm wide. You will need about 10 to 14 strips depending on how much or how little filling you'd like to show through. Spend some time making extra decorations like flowers, leaves or strips of plaited dough to cover the circumference of the pie dish.
• Remove your tart tin from the fridge and fill the dish with the cooled berry filling.
• Use your prepared pastry to lattice and decorate your mulberry pie.
• Bake in the oven for about 40min or until gold brown.
• Once cooked, allow to cool to room temperature before slicing.