In a bowl mix together the filling ingredients. Cut four 12cm diameter rounds from each sheet of the pastry. Lightly brush the edges with the beaten egg. Spoon 1 tablespoon of the filling onto the centre of each pastry round. Fold the pastry over to create a semicircle. Press down on the edges to create a seal. If desired, crimp the edges.
Set up your barbecue for indirect cooking (refer to your handbook for further instructions). Preheat your barbecue for roasting.
Place the pasties onto two lined baking trays, and pierce two holes in each pasty with a knife. Brush the pasties with the egg.
Once the barbecue has preheated, make adjustments to the burner control(s) if required. Cook the pasties until golden brown and crisp, 20 to 25 minutes for each tray.