pastel de nata (egg custard tarts)

These custard tarts are so achingly delicious, crisp and flaky, I can only have them a few times a year because of the risk that overexposure might lead to apathy.

Makes 12 tarts

1 pack ready-rolled pull-pastry (375g is standard in most supermarkets)
1 whole egg
2 egg yolks
120g caster sugar
2 tbsp cornflour
400ml whole milk
Zest of 1/2 lemon

Take the pastry out of the fridge and packaging at least 30 minutes before unrolling.

Place the egg, egg yolks, sugar and cornflour in a cold pan and mix until combined. Pour in the milk and gently whisk until you have a smooth liquid. Place the pan on a medium-low heat while continuing to whisk. The secret to smooth custard is to take your time; if the heat is too high, you risk making scrambled eggs.

Once it starts to thicken you can turn the heat up very slightly and continue to stir for another
5 minutes. Remove from the heat and add the lemon zest. The custard should have a thick yet pourable consistency. Pour the custard into a glass bowl and cover with clingfilm to prevent a skin from forming.

I leaf your oven to 220C (240C non-fan). Unroll the pastry and remove the plastic. Cut it in half lengthways and place the sheets on top of each other. With the long side facing you, roll the pastry tightly into a long sausage and cut into 12 discs.

Place each disc in a lightly greased muffin tin. Dip your thumbs into some water and press into the middle of each round. Flatten the bottom and push the pastry up the edges --it is OK if the edges come up a little above the tin. Divide the cooled custard between the 12 pastry cases and bake for 20-25 minutes. You want the tops of the tarts to be burnished with black spots and the insides still soft, with a little wobble.

Leave the tarts to cool and enjoy them like the Portuguese do, with a small coffee.