rest it for an hour in the fridge or over night, if you wish.
Preheat your oven to 180 degrees and line the base of an 8 inch tart tin. Grease and flour around the edges.
Roll the pastry on a flour dusted surface and cut in a circle that will easily fit into the tin. The pastry will need to come right up to the lip of the tin and not be forced into corners. If it is not gently placed it will shrink when baking. Bake the pastry case blind for twenty minutes, using a sheet of parchment and beans or coins.
In the meantime whisk the egg yolks and sugar in a large bowl until they are pale in colour.
Add the vanilla, mandarin peel and nutmeg to the milk and cream in a heavy based saucepan. Gently heat the mixture until it is shivering on top — just before it starts to completely boil.
Whisk the cream mixture into the egg yolks in a continuous steady stream. If necessary strain the custard to remove and lumps.
Pour the custard into the prepared tart case and sprinkle a little more nutmeg over the top. Bake for 40 minutes or until there is only the slightest wobble in the center and it is pale golden on the top. Allow the tart to cool completely before removing it from the tin and topping it with some of the caramalised mandarin slices.