Grease two 20cm springform cake tins with vegetable fat.
Boil potatoes for 15 minutes until tender, then drain and chop into bite-size pieces.
Soak lentils in boiling water for five minutes and drain.
Fry spices, curry leaves, lentils, chillies, and onion in oil for five minutes before adding remaining veggie ingredients.
Toast coriander seeds and whole chillies over low heat until they change colour.
Crush coriander seeds and set aside, then fry fenugreek, chillies, and onions until browned.
Add aromatics and chicken, fry for five minutes, then simmer with tomatoes and remaining spices for 15 minutes.
Preheat the oven to 200°C.
Rub butter into flours and pour in a boiling mixture of 400ml water, salt, and fat.
Knead the mixture on a floured surface to form a smooth dough.
Divide two-thirds of the dough in half and line the prepared tins.
Pack the cooled vegetarian and chicken fillings into their respective tins.
Roll out the remaining pastry to create lids for both pies.
Seal lids with egg yolk, crimp edges, make steam slits, and glaze with more egg.
Bake for 1 hour until golden and cool on a wire rack.