Pastel de nata

Preparing the tart shells:

1. 1Roll the puff pastry lengthwise into a log shape.
2. 2Cut the log into 10 equal pieces.
3. 3Place them vertically into the buttered cups of a muffin tin.
4. 4Press the dough into the molds, pushing it to fit the shape and bring the dough up the sides.
5. 5Set aside in the refrigerator.

Preparing the filling:

1. 6Pour the water, sugar, ground cinnamon, and lemon zest into a saucepan.
2. 7Bring to a boil and cook to 105°C.
3. 8Remove from the heat and strain the syrup to remove the zest, then let cool slightly.
4. 9In another saucepan, put the flour and gradually add the milk while whisking to avoid lumps.
5. 10When the mixture is smooth, cook over low heat until thickened, stirring constantly.
6. 11Remove the saucepan from the heat and add the syrup to the milk-flour mixture in small amounts while whisking.
7. 12Finally add the egg yolks and mix.
8. 13Divide the custard among the puff pastry shells.

Baking the pastéis de nata:

1. 14Bake in an oven at 250°C for 15 to 18 minutes.