Gingery beef and mushroom pie

Method

1. Heat the oil in a large wide pan (a large sauté pan or wok works best), then cook the beef, garlic, chillies and ginger over a high heat, stirring often, for about 5 minutes until the mince is browned.
2. Add the mushrooms, stock, star anise, oyster sauce and soy. Cover, then simmer gently for 20 minutes. Remove from the heat, stir in the pak choi and coriander, then set aside to cool. Preheat the oven to 200°C/fan180°C/gas 6.
3. Divide the cooled filling between 2 x 1.3 litre pie dishes. Brush the rims of the dishes with a little milk. Unroll the pastry and use it to cover the dishes, crimping the edges to seal and trimming any excess pastry. Open-freeze one pie for 1-2 hours until firm, then wrap tightly in cling film and store in the freezer for up to 3 months. Cook from frozen, adding 10 minutes to the cooking time (below).
4. Brush the other pie with milk and bake for 25-30 minutes until golden brown and piping hot.