Pastéis de Nata (Portuguese Custard Tarts)

Instructions

1. Heat the oven to its highest setting, at least 250°C (480°F), with a rack in the upper third. Grease a 12-hole muffin tin with butter.
2. Unroll the pastry on a lightly floured surface and roll it up tightly from the short side into a log. Cut the log into 12 equal slices and set each slice cut-side up in a hole of the tin.
3. Wet your thumbs in cold water, press each slice flat in the center, then work the pastry up the sides until the wall is thin and stands just above the rim. Chill the tin for 20 minutes.
4. Whisk the flour with 100 ml (scant 1/2 cup) of the milk until smooth, then whisk in the rest of the milk. Cook over medium heat, stirring constantly, for 4 to 5 minutes until it thickens like a loose pudding.
5. In a small pan, boil the sugar, water, cinnamon stick and lemon zest for about 5 minutes without stirring, until the syrup is slightly thick. Discard the cinnamon and zest, then pour the syrup into the milk mixture in a thin stream, whisking.
6. Let the mixture cool for 10 minutes, then whisk in the egg yolks and vanilla. Pass the custard through a fine sieve into a jug so it is completely smooth.
7. Fill each pastry case about three-quarters full. Bake on the upper rack for 12 to 15 minutes, until the pastry is golden and the custard tops are speckled with dark brown spots.
8. Cool in the tin for 5 minutes, then move to a rack. Serve warm or at room temperature, dusted with cinnamon and powdered sugar if you like.

Tips

• The dark blisters are the signature. If your oven tops out at 220°C (425°F), bake on the highest rack and finish under the broiler (grill) for 1 to 2 minutes, watching closely.
• Keep the pastry cold. If the slices soften while you shape them, return the tin to the fridge for 15 minutes before filling, which keeps the layers flaky.