Method:

1. Heat the oil in a deep skillet over medium heat and fry the onions until golden brown. Remove from the oil with a slotted spoon and drain on paper towels. Turn off heat, keeping oil in the pan. 

2. Grind the onions into a smooth paste in a food processor. Remove to a bowl and set aside.

3. In the food processor, grind the tomatoes and garlic and ginger pastes together into a smooth paste. 

4. Heat the oil in the skillet again and add the onion paste. Fry for 2 to 3 minutes. Add the tomato paste and all the spices. Mix well. 

5. Fry the masala until the oil begins to separate from it. 

6. Add the chicken to the masala and brown well, about 8 minutes.

7. Add 1 1/2 cups of hot water to the chicken, simmer, and cover. Cook until the chicken is tender, about 15 minutes. 

8. Garnish with chopped coriander and serve with hot chapatis (Indian flatbread), Naans (tandoor-baked Indian flatbread) or plain boiled rice.