Cut the chicken breast fillets into roughly 2-3cm cubes and season all over with salt and pepper.
Heat the extra-virgin olive oil in a large frying pan over a medium heat. Add the chopped onion and fry for 5–7 minutes until soft and translucent.
Add the chopped garlic and cook for another minute.
Increase the heat, add the chicken and brown on all sides without cooking it through.
Sprinkle the curry powder over the chicken and onions, stir well and cook for 1 minute.
Pour in the coconut milk, chicken stock (or water) and tomato purée, then bring to the boil.
Reduce the heat, cover and simmer for 15–20 minutes, uncovering for the last 5 minutes if the sauce is too thin.
Meanwhile, cook the basmati rice according to the packet instructions.
Serve the curry piping hot, scattered with chopped fresh coriander if you like.