Martha Collison's pastéis de nata

1. Unroll the pastry sheet from its packaging and tightly roll it back up again, squeezing well to fuse the pastry together. Wrap the pastry log in baking parchment and chill for at least 1 hour before using.

2. Whisk together the flour and 3 tbsp of the milk in a medium bowl to form a smooth paste. Heat the remaining milk in a small pan until just boiling, then slowly whisk the hot milk into the paste until smooth.

3. Meanwhile, in another small pan mix together the caster sugar with 75ml water and gently heat until the sugar has dissolved, then add the cinnamon stick and turn up the heat. Simmer the mixture until it reaches 105°C on a sugar thermometer, then remove from the heat and discard the cinnamon stick.

4. Gradually whisk the syrup into the milk mixture, until it is well incorporated. Pour this mixture back into the pan and heat very gently for 2-3 minutes, whisking all the time until the mixture is just thick enough to coat the back of a spoon. Pour back into the bowl and allow to cool to room temperature, whisking occasionally.

5. Lightly grease 10 holes of a muffin tin (or pastéis de nata tins, if you have them) with butter. Slice the ends off the pastry log, then divide into 12 even-sized rounds (you’ll have 2 spare pieces, but dividing into 12 creates portions of just the right size). Place one round of pastry into each hole.

6. Fill a small container with water and keep nearby. With wet fingers and thumbs, push into the centre of the pastry round to create a well. Use your fingers to draw it up the sides of the tin, pressing it firmly against the mould to create a thin pastry case. Repeat with each piece of pastry, then chill the muffin tin for at least 15 minutes.

7. Preheat the oven to 250°C, gas mark 9 with a baking tray inside on the top shelf to heat up. Whisk the egg yolks, one at a time, into the cooled milk mixture until smooth. Strain this egg custard through a sieve to remove any lumps.

8. Divide the egg custard evenly between the tarts and place the muffin tin onto the preheated baking tray and bake at the top of the oven for 10-12 minutes. The tarts will puff up and the custard will bubble. After 10-12 minutes, switch the oven to the grill setting and bake for a further 1-2 minutes. Keep a close eye on the tarts while grilling, you want an irregular browning on the top to give them their characteristic caramelised flavour.

9. Remove from the oven and leave to stand in the tin until they are cool enough to handle. The filling should be beautifully smooth. Enjoy warm and dusted with cinnamon. These tarts are best eaten on the day of making.