Method

Unroll the sheet of puff pastry and grate over half the zest of one orange. Roll up horizontally to make a long sausage, then cut into 12 pieces.
Press each piece, coil side up under your palm to create a disc, then press each disc into a non-stick cupcake tin. Refrigerate for at least an hour.
In a pan, add the milk, Cointreau and remaining orange zest until it starts to bubble then set aside to cool for 10 minutes.
Pop the flour into a large mixing bowl then slowly add in the milk mixture, beating well until a smooth paste is formed, then slowly add one egg yolk at a time, beating it into the batter.
In another small pan, heat the sugar and 100ml of water. Boil for three minutes until all of the sugar has dissolved then carefully whisk into the batter to form a custard.
Pour the custard into a clean pan and cook over a low heat for 6-8 minutes or until thickened then allow to cool for 20 minutes.
Preheat the oven to 200C fan, and spoon the custard into the pastry cases. Bake for 20 mins until the pastry is crispy and flakey and the top is dark, even slightly burnt in places.
Allow to cool in the tin before turning out and serving.