1. For the filling cut all the chicken into 1.5cm chunks. Heat the oil in a sauté pan or wide saucepan over a medium low heat. Add the shallots, garlic, chilli and ginger and fry gently for a few minutes until soft but not coloured.
2. Stir in the curry paste and cook for a minute or two. Add the chicken. Increase the heat a little and cook, stirring until it has lost it’s raw look. Add the coconut cream, chicken stock, lime leaves, lemongrass and sweet potato. Simmer for 12-15 minutes, until the sweet potato is tender.
3. Add the cornflour liquid, bring to a simmer and stir until the sauce begins to thicken, then take off the heat. Taste the sauce and season with pepper and a little fish sauce. Set aside to cool.
4. To make the pastry, put the flour and salt in a bowl. Add the diced butter and lard and rub in with your fingertips until the mixture looks like fine breadcrumbs. Alternatively, do this in a food processor or a mixer and then transfer to a bowl.
5. Now work in just enough cold water to bring the pastry together. When the dough begins to stick together use your hands to gently knead it into a ball. Wrap the pastry in cling film and place in the fridge to rest for about 30 minutes.
6. Heat your oven to 200°C/gas6.
7. Remove the lemongrass and lime leaves from the cooked pie filling if you prefer and transfer to a 1.2 litre pie dish.
8. Roll out the pastry on a lightly floured surface and cut a 2cm wide strip of pastry. Dampen the rim of the pie dish with water, press the pastry strip onto it and dampen this too. Use a pastry lattice cutter to cut a pattern in the remaining piece of pastry. Pull the pastry very gently to open up the lattice, then place over the pie. Press the edges down to seal, then trim away the excess pastry.
9. Brush the top of the pie with beaten egg then bake in the oven for about 30 mintues, until golden. Leave the pie to sit in the tin for 5 minutes before serving with steamed or stir-fried greens.
Taken from Paul Hollywood’s Pies & Puds, published by Bloomsbury
Photograph © Peter Cassidy