For the chicken, combine the chicken, ginger, garlic and vegetable oil in a shallow non-reactive dish. Cover and leave in the fridge to marinate for at least one hour.
For the basmati rice, place the rice into a pan with a lid. Add the water and bring to the boil over a medium heat with the lid on. Once boiling, reduce to a simmer and cook for 8-10 minutes. Remove from the heat and leave to stand for at least 10 minutes before serving.
Meanwhile, for the curry, heat the oil in a large pan over a medium heat. Add the onion and cook for 10 minutes, or until the onion has softened and has taken on some colour. Add the garlic and ginger and cook for a further five minutes. Add the curry powder and cook for two minutes.
Stir in the coconut milk, chicken stock and tomatoes. Bring to the boil and add the potatoes. Simmer for about 10 minutes, or until the potatoes are just tender. Add the chickpeas and bring back to the boil. Simmer for two minutes.
To cook the chicken, heat a splash of oil in a frying pan over a high heat. Cook the chicken on all sides until golden-brown and cooked through. Reserve the chicken, covered, in a warm place until ready to serve.
To serve, place generous amounts of the curry and chicken onto the rice on plates. Garnish with the chopped coriander.