Heat the oil in a large saucepan over a medium heat.
Add the cinnamon sticks, black peppercorns and black cardamom. Fry for 1 minute until fragrant.
Add the sliced onions and cook for 5–6 minutes, stirring regularly, until golden brown.
Stir in the ginger paste, garlic paste and green chilli paste. Cook for 1–2 minutes until the raw aroma disappears.
Add the chicken and cook for 6–8 minutes, stirring occasionally, until lightly browned on all sides.
Stir in the spices and dried fenugreek, mixing well so the chicken is evenly coated. Cook for 3–4 minutes.
Add the puréed tomatoes and cook for 4–5 minutes, stirring occasionally, until the tomatoes have reduced and the oil begins to separate around the edges.
Pour in the water and stir well. Bring to the boil, then reduce the heat to a gentle simmer.
Cover with a lid and cook for 15–20 minutes, or until the chicken is fully cooked and tender.
Stir in the chopped coriander and simmer for a further 1 minute.
Serve hot with naan or rice.
