In the bowl of a food processor, add the butter, flour and sugar. Pulse until mixture resembles coarse breadcrumbs.
With the motor running, add the egg yolks and then the ice water, spoon by spoon until the mixture comes together in a ball in the food processor.
Remove from the food processor then knead until the dough is smooth then wrap in cling wrap and refrigerate for 30 minutes.
Pre-heat the oven to 180ºc,
When the pastry has chilled, roll it out on a floured surface and transfer to a 30cm pie dish/tart case.
Line with baking paper and fill with dried beans/rice and bake for 10 minutes. After 10 minutes, remove the baking paper and beans and bake for another 10 minutes or until golden brown and crisp.
In the meantime, bring the milk, cream, sugar and vanilla to a boil in a large saucepan.
In a separate bowl, whisk together the egg yolks and the cornflour.
When the milk has reached boiling point, lower the heat.
Whilst whisking, ladle in half of the milk mixture to temper the eggs.
Through a sieve, pour this mixture back in the pot and whisk continuously over medium heat until the custard is thick and smooth. Allow to cook gently, whilst still stirring, until the custard is cooked (it should have no floury taste).
Stir in the chopped bananas and pour the custard into the pastry case.
Place a piece of cling wrap directly on the surface of the custard (to prevent it from forming a skin) and place in the fridge.
Refrigerate for 2-3 hours until the custard is set and chilled through.
When you are ready to serve, whip the cream with the sugar until soft peaks form.
Top the pie with the sliced bananas and add the cream. Finish with chocolate shavings and serve.