For the chicken thighs, put a large frying pan on a high heat and add two tablespoons of oil. Once hot, add the chicken thighs skin-side down and cook for 3-4 minutes, or until golden-brown on each side. Put the chicken on a plate and set aside.
Heat a large frying pan and add the rest of the oil. Once hot, add the onions, garlic, ginger and red pepper. Cook until soft, then remove from the heat and leave to cool. Tip the mixture into a blender or food processor and blend until smooth.
Add the purée back to the pan and cook over a low heat for 5-10 minutes.
Add the tomato purée, curry paste, garam masala, fenugreek leaves, ground coriander and fresh turmeric and cook for a further five minutes.
Place the chicken thighs back in the sauce and simmer for 20 minutes.
For the pilau rice, heat a large saucepan and add the oil. Once hot, add the cumin, cardamom, cinnamon, black pepper and bay leaf. Once they start to pop, add the rice and continue to stir until the rice is lightly toasted.
Add 650ml/1¼ pint water and the salt and bring to the boil. Place a lid on top and turn the heat to low. Leave to steam for 20-30 minutes.
Just before serving mix in the butter with a fork.
To serve, place the rice on the plate and the curry to one side. Garnish with the chilli and coriander.