Start by preheating your oven to 450°F (230°C). High heat is crucial for getting that enticingly crispy crust.

If you’re using store-bought puff pastry, discard it from the package and let it come to room temperature. If you’re brave enough to make your own, roll it out into a thin layer. Cut out circles that are about 4 inches in diameter, which will fit neatly into your muffin tin. Press these circles into the tin to form the tart shells.

In a medium saucepan, combine the milk, sugar, flour, and water. Whisk these ingredients together until smooth. Add the cinnamon stick, lemon peel, and nutmeg. Turn on the heat to medium and bring the mixture to a gentle simmer, stirring continuously.

Once the mixture is simmering and well combined, remove it from the heat. In a separate bowl, whisk the egg yolks together. Gradually add a small amount of the hot mixture to the yolks, stirring constantly. This step is critical; it prevents the eggs from scrambling. Once tempered, pour the egg mixture back into the saucepan, stirring until fully combined.

To ensure a silky texture, strain the custard through a fine sieve into a clean bowl. Discard the solids. This step might feel tedious, but trust me, it’s worth it.

Pour the cooled custard into each pastry shell, filling them about three-quarters full. You want some space for the custard to puff up while baking.

Place the muffin tin in the preheated oven. Bake for about 15-20 minutes or until the tops are golden brown and slightly charred in spots. Keep an eye on them; every oven is different, and you want that perfect balance between crispy and soft.

Once they’re done, take them out of the oven and let them cool in the tin for about 10 minutes. Then carefully remove them and transfer them to a wire rack to cool completely. They are best enjoyed warm or at room temperature.