To a food processor add flour, caster and chopped cold butter, blitz until all the butter and flour have turned into bread crumb like.
Add half of the cold water and turn on the food processor at a low speed, add a teaspoon of water at a time until a dough forms. As soon as the dough turns into a ball turn off the food processor.
Remove the dough from the food processor and wrap in cling film, then place in the fridge to chill for at least 30 minutes.
After 30 minutes, remove from the fridge on to a floured work surface and start to roll out the pastry.
Roll the pastry until about 2-3 mm thick and large enough to cover the base of your tart tin.
Place the pastry over the tart tin, and then press down in the corners and trim the sides.
Blind bake the pastry, using some baking paper and dried beans or blind bake beans.
Bake for about 15-20 minutes until golden brown at 180c.
In a sauce pan add the 500ml milk, sugar and saffron over medium heat.
To the remaining milk, stir in custard powder until smooth.
Add the mango pulp and cardamom to heated milk and stir well.
Add the custard mixture to the sauce pan and bring the boil, once the custard thickens remove from the heat.
Allow the mixture to cool for a minute or two, then pour into the pastry tin.
Place the tart tin in the fridge to chill for at least 2 hours or overnight.
Whipped the double cream and icing sugar until nice and thick.
Spread the thick whipped cream of the mango custard.
Peel and thinly slice the mango into long strips.
Stand the mango slices in the cream starting on the side, placing each one next to each other all the way around in a large spiral, then slice and enjoy!