Heat the oil in a large pan over medium heat until hot.
Add sliced onions and fry for 8–10 minutes until golden brown.
Stir in grated ginger and garlic and cook for 2 minutes until aromatic.
Add tomatoes, red chilli powder, turmeric, coriander, cumin, and paprika. Cook for 5–7 minutes until oil separates.
Add chicken and coat thoroughly with masala. Cook for 5 minutes.
Add 100 ml water, cover, and simmer for 25–30 minutes until chicken is tender.
Add garam masala and green chillies. Cook uncovered for 2–3 minutes.
Garnish with chopped coriander and serve hot.
