1. Heat the oil in a large frying pan. Brown the mince thoroughly, using a wooden spoon to break it down.
2. Add the rest of the ingredients for the filling to the pan and stir-fry over a high heat for 10 minutes until the mixture is fairly dry. Leave to cool while you roll out the pastry.
3. Preheat the oven to 220C/425F/gas mark 7. On a lightly floured surface, roll out the pastry thinly and stamp out as many 10cm rounds as possible, re-rolling the pastry as necessary. Brush the outside edge of each with water then fill them generously (using about 1½ tbsp mixture). Fold in half and seal well, pressing the edges with a fork. Prick the top of each.
4. Arrange on baking trays, brush with beaten egg or milk, and cook towards the top of the oven for 20 minutes or until golden brown. Best served warm.