For the curry powder, heat a wide heavy-based pan over a medium–high heat. Once hot, add the basmati rice and cook for a few minutes.
When starting to brown, add the coriander seeds, cinnamon pieces and black peppercorns and toast for a few minutes while stirring. (You can tell when they are almost roasted as the seeds should start to pop and break when squeezed in the hand.)
Add the dried chilli, cumin seeds and fennel seeds and continue to roast in the pan for a further 5 minutes, until fragrant and toasted. Remove from the heat and transfer to a large bowl and allow to cool.
Once cool, grind the spices in a spice grinder or pestle and mortar until you have a fine powder.
For the curry, heat the oil in a large pan and add the curry leaves, onion, garlic and ginger. Cook for 5–10 minutes until the onions are soft and lightly browned. Add the chicken pieces to the pan and allow to brown, whilst stirring frequently.
Stir in the roasted curry powder, stir well to evenly coat all the chicken pieces and continue to cook for a further 5–10 minutes. Add the coconut milk and pour in a cup of water (approximately 250ml/9fl oz). Sprinkle in a teaspoon of salt, bring to the boil, then reduce the heat and cover with a lid.
Allow the curry to simmer gently for around 30 minutes, until the chicken is cooked through. Remove the lid and allow the sauce to reduce for a further 5–10 minutes to thicken. Stir occasionally and if you think the curry needs a little more coconut milk, add during cooking.
Transfer to a serving dish and sprinkle with freshly chopped coriander to serve. Serve with steamed rice