Sift the flour into a mixing bowl, rub in the butter until the mixture resembles coarse breadcrumbs.
Add the water slowly to the mix and bring together until a dough is formed.
Wrap the dough in cling film and chill in the fridge for 30 minutes.
To make the crème patisserie, warm the milk in a small saucepan.
In a separate bowl whisk together the yolks and sugar until smooth.
Sift in the flour and combine.
Add the warm milk to the mixture, whisking constantly.
Pour this mix back into the saucepan, gently bring to the boil. Continue whisking until thick and creamy.
Remove from the heat and set aside to cool.
Preheat the oven to 180°C/350°F/Gas 4.
Roll out the pastry and use it to line the mini tart tins.
Prick the base of each with a fork.
Cover 8 mini tart tins with baking paper and fill with baking beans, bake in the oven for 12 minutes (this is known as blind baking).
Remove from the oven and leave to cool completely.
Fill the tartlets with the crème patisserie and smooth out with a spatula.
Arrange the fruits on top and serve.