Portuguese Custard Tarts

Ingredients:
3 egg yolks
115g (4 oz or ½ cup) caster sugar
2 Tbsp corn flour
230 ml (7¾ fl oz) cream
170 ml (5½ fl oz or ⅔ cup) milk
2 tsp natural vanilla extract
1 sheet ready-rolled puff pastry

Method:

1. Put the egg yolks, sugar and cornflour in a saucepan and whisk together. Gradually whisk in the cream and milk until smooth. 
2. Place the pan over medium heat and cook, stirring, until the mixture thickens and comes to the boil. Remove from the heat and stir in the vanilla extract. Transfer the custard to a bowl, cover the surface with plastic wrap to prevent a skim forming and leave to cool.
3. Preheat the oven to 190°C. Lightly grease a 12-hole 80 ml (2½ fl oz or ⅓ cup) muffin tin. 
4. Cut the pastry sheet in half, put one half on top of the other and set aside for 5 minutes. 
5. Roll up the pastry tightly from the short end and cut the pastry log into twelve 1 cm (½") rounds. 
6. Lay each pastry round on a lightly floured surface and use a rolling pin to roll out until each is 10 cm (4") in diameter.
7. Press the pastry rounds into the muffin tin. Spoon the cooled custard into the pastry cases and bake for 20-25 mins, or until the pastry and custard are golden. 
8. Leave the tarts in the tin for 5 mins, then transfer to a wire rack to cool completely.

Makes 12
Adapted from Bill Granger's Everyday Cookbook