Heat oil and add cumin, star anise, bay leaves, and dried red chillies. When the cumin begins to splutter, add garam masala and onions. Sauté until the onions have softened.
Add the garlic-ginger paste, turmeric, ground coriander, ground chillies, and salt. Toss the spices on a low heat until the mixture releases the oil.
Add the chicken and the tomatoes. Stir well.
Reduce the heat to a fast simmer. Boil the water and pour over the chicken.
Cover and simmer for 20 minutes.
Remove the lid and reduce to achieve the consistency of the gravy you want.
Garnish with chopped coriander.