Make the filling
1. Heat olive oil in a large heavy-based saucepan over a medium heat. Add cumin seeds and mustard seeds and cook until they begin to pop, about 30 seconds.
2. Lower heat and add the onion and cook until soft and just beginning to colour. Add garlic and ginger and cook for a further 30 seconds.
3. Add chicken pieces, cayenne pepper, paprika, salt and curry leaves. Stir over heat for 1 minute.
4. Pour in 250ml water and bring to a simmer. Simmer gently for 20 minutes stirring occasionally.
5. Remove lid after 15 minutes and let liquid evaporate a bit. Add coconut milk and heat through.
6. Make a paste with cornflour and a little cold water and stir in to thicken sauce. The mixture should be quite thick. Set aside to cool.
7. Heat olive oil in a large frying pan with cumin and fennel seeds and cook until aromatic.
8. Add eggplant chunks and pan-fry until soft and golden. Stir through chicken filling. Leave to cool.
9. Preheat the oven to 200°C.
10. Roll out the pastry on a lightly-floured bench top to 55mm thickness. Using your pie dish as your guide, cut a circle slightly larger than the dish, then cut a strip of pastry to fit around the edge of dish. Run a wet finger around edge or use egg wash, then place on pastry strip. Brush pastry strip with egg wash. Repeat with remaining pie dishes.
11. Divide cooled mixture between pie dishes and place on pastry lid. Trim away any excess pastry and press with your thumb to seal. Using a sharp knife ‘knock up’ edges of pastry. Make a slit in the top of pastry to allow steam to escape.
12. Brush pastry top with egg wash.
13. Place in the oven and bake for 20 minutes until golden and the filling bubbling hot. For 1 larger pie bake 25-30 minutes.