To make the curry paste, finely chop the onion, chilli, garlic, lemongrass, galangal and turmeric in a food processor until the mixture is a thick paste.

Cut the chicken through the bone into bit sized pieces.

Heat the oil and cook the curry paste over a low heat for 10 minutes.

Add the chicken and fry for 2 minutes, making sure the curry paste coats the chicken.

Add the coconut milk , water, 6 finger limes quartered lengthwise and shredded kaffir lime leaves and simmer until the chicken is tender, approximately 25 minutes.

Discard the finger limes, add the fish sauce, scatter with coriander leaves and serve with the remaining finger limes quartered lengthwise on steamed rice.