Put both flours, the turmeric, and a few grinds of black pepper into a large, heatproof bowl.
Rub in the butter until the mixture resembles fine crumbs. Make a well in the center of the mixture.
Melt the vegetable shortening with salt and 2/3 cup water in a medium pan over a low heat. Bring the mixture to a boil and then tip into the well of the flour mixture.
Using a wooden spoon, mix everything together.
When the dough is cool enough to handle, tip out the dough and knead for about 5 minutes. The dough should be smooth and pliable.
Cut off one quarter of the dough (for the lid), wrap in cling film and set aside.
Roll out the remaining dough into a disc about 1 cm thick. Set the disc on top of a cling-film covered cake tin base
Mold the pastry around the base and be sure to work out and pleats Chill for 1 hour or until firm.
Roll out the reserved pastry into a disc slightly larger than the top of the tin. Cover and set aside. Re-roll any trimming to use as decorations as desired.
Heat the oven to 400°F
Remove the cake tin from the dough with the pie case set upright. Spoon the potato curry (or desired filling) not the pastry case. Make sure the sides are slightly higher than the filling.
Brush the rim of the base and the rim of the tope with beaten egg.
Pinch the edges of the lid and base together to seal. Crim the edges with a fork.
Brush the beaten egg all over and attach any pastry shapes and glaze the shapes as well. Cut a couple of steam holes in the top of the pie.
Bake the pie for about 55 to 60 minutes or until golden and crisp. Remove from the oven and leave to cool. Top with mango salsa as desired!
Enjoy!!