Blanch the hazelnuts with boiling water and set aside. When cool, remove and discard the skin.
Put half of them into a small food processor and blitz until get a coarse mixture. Add about half of the yogurt and combine. You should get a thick paste.
Finely chop the rest of the hazelnuts and mix with the mincemeat.
Preheat the oven to 180°C.
Unroll the pastry. With a pastry cutter or a mug, stamp out circles (about 6-8 cm in diameter). If you want a lid, stamp out stars shapes too with a cookie cutter.
Press the rounds lightly into the holes of a shallow muffin or pie tin. Prick the bases with a fork.
Add a small spoonful of the paste, followed by a spoonful of mincemeat. Don’t overload them!
Top them with the stars, lightly pressing the tips and the pie edge together.
Put the tin into the oven and bake the mince pies for about 15 minutes, or until they’re golden brown and the pastry has cooked through properly.
Transfer them onto a wire rack and let them cool.
Dust with icing sugar just before serving.