Heat the oven to 180C/160C fan/gas 4. Take a sheet of shortcrust pastry and use a 10cm cookie cutter to cut 12 circles into the pastry. Press each circle into the holes of a cupcake tray. Scrunch up squares of baking paper, then use to line each of the pastry cases. Fill each with baking beans or uncooked rice, pressing them in a little, and bake for 10 mins. Remove the beans/rice and the baking paper and bake for 5 mins more, until the base is starting to colour slightly. Remove from the oven and reduce the temperature to 140C/120C fan/gas 1.
Bring the cream, milk, vanilla bean paste and a small grating of nutmeg to the boil. Beat the egg yolks with the sugar until pale, then pour the hot milk and cream over, beating as you go. Strain custard into a jug, allow to settle for a few mins, then skim off any froth.
Pour the custard into each of the tart cases, filling them as high as you can. Grate over a little more nutmeg on each, then carefully place back into the oven and bake for 15-20 mins, until the tarts look set with a slight wobble. Remove and cool, serve with a little more nutmeg freshly grated over the top.