While the filling is cooling, make the pastry.
In a food processor whizz together the butter, flour, baking powder, turmeric and a pinch of salt until it resembles a rough crumb texture. Add eggs, and a bit of cold water if you need to, until the dough comes together. Wrap in cling film and chill.
Preheat the oven to Fan180'C/200'F/Gas 6. Thinly roll out the pastry and use an 19cm plate to cut out six circles (I used my trifle bowl) – re-roll the pastry as necessary. Place the cooled pork filling on half of the pastry. Brush the edge with milk and fold the pastry over the filling, pinch the edges together to seal.
Place on a baking parchment lined tray or two, brush with milk and prick the tops to let the steam escape. Place in the oven and bake for 25 – 30 minutes until golden.