Firstly heat the oil in a wok or large pan over a high heat, then add the bay leaves and stir for a few minutes before adding 1 1/2 onions, chopped, then cook and stir until soft, about 4 to 6 minutes. Once the onions are soft add one tablespoon of water followed by the turmeric, paprika, chilli powder, garlic and ginger and stir. Once stirred, add another tablespoon of water.
Reduce the heat to medium and add the diced chicken breasts and sliced tomato. Toss the chicken in the wok or pan until coated then add the cinnamon stick, crushed cardamom pods, cloves, sugar, a knob of butter and 1 tablespoon of water. Cover and let cook for 30 minutes.
After 30 minutes, the curry should be very watery. Remove a ladle full of water and mix in the curry paste then pour over the chicken. (Bare in mind the curry paste is optional but I do feel like it gives a stronger taste and darker colour.) After 5 minutes stir in the ground coriander and cook for a couple more minutes. If you want a thicker sauce then increase the heat to high and cook until it reaches the desired consistency.
In a separate frying pan over a high heat, warm a little oil and fry the remaining 1/2 onion until golden brown, about 6 to 8 minutes. Serve the curry over rice with some of the onions and fresh coriander sprinkled on top.