Portugese custard tarts

I'd recently had an addiction to Portugese tarts and would try one from a different bakery each week and finally decided to try them myself.
Like many things that i bake,i made these one night after work and didn't have much time so i think next time i'd have more time and cut perfect round pastry to make them all look identical.These actually tasted better later in the day after a few hours in the fridge.

Makes 12
From Bill Granger's Every day

3 egg yolks
115g (1/2 cup) caster (superfine) sugar
2 T cornflour
230 ml cream
170 ml milk
2 t natural vanilla extract
1 sheet ready rolled puff pastry

Put the egg yolks, sugar and cornflour in a saucepan and whisk together .Gradually whisk in the cream and milk until smooth . Place the pan over medium heat and cook, stirring until the mixture thickens and comes to the boil. Remove from heat and stir in the vanilla extract. Transfer the custard to a bowl, cover the surface with plastic wrap to prevent a skin forming and leave to cool.
Preheat the oven to 190 degrees Celsius. Lightly grease a 12 hole muffin tin.Cut the pastry sheet in half, put one half on top of the other and set aside for 5 mins. Roll up the pastry tightly from the short end and cut the pastry log into 12 1 cm rounds. Lay each pastry round on a lightly floured surface and use a rolling pin to roll out until each is 10 cm in diameter.
Press the pastry rounds into the muffin tin. Spoon the cooled custard into the pastry cases and bake for 20-25 minutes, or until the pastry and custard are golden. Leave the tarts in the tin for 5 mins then transfer to a wire rack to cool completely.