Pre-heat the oven to 200°C. Roll the pastry out to 1cm thickness on a lightly floured surface and use it to line a 7 inch flan ring placed on a lined baking tray. Line the inside with nonstick baking paper and fill with baking beans. Blind bake the pastry for 10-12 minutes until it is starting to turn golden brown in colour. Remove from the oven and remove the baking paper and the baking beans. Turn the oven down to 170°C. Allow it to cool.
Meanwhile, prepare the filling by whisking together the egg yolks and sugar until pale and thick. Add the cream and nutmeg and mix well, then pass through a fine sieve into a saucepan and heat over a medium heat to blood temperature. Pour the custard into the baked pastry case (still on the baking tray) so that it comes almost all the way to the top.
Carefully transfer it to the oven and bake for 35-40 minutes until just set and golden brown on top. Remove from the oven and allow to cool before turning out onto a cutting board. Use a sharp knife to carefully cut portions of the tart and serve them stacked on a plate.