Place the potato, onion and meat in a basin and mix well.
Place the flour in a bowl. Add the butter and lard, rub in until the mixture resembles fine breadcrumbs. Add about 2 tablespoons of water and mix to form a firm dough. Turn out onto a floured surface and knead lightly.
Divide the pastry into 4.
Roll out each piece to about 15 – 18 cm (6 – 7 inches). Trim by cutting round the edge of a small plate.
Divide the filling between each round. Brush the edges with water and draw up the pastry on each pasty, in a line over the centre of the filling. Seal well. Flute the edge with your fingers.
Place the pasties on a baking sheet, fluted edges uppermost. Brush each with a little beaten egg or milk. Bake for 40 – 45 minutes, until golden brown.