Heat the vegetable oil in a large, heavy-bottomed pan or pot over medium heat.
Add the cumin seeds, cinnamon stick, green cardamom pods, cloves, and bay leaf. Sauté for a minute or until they start to crackle and become fragrant.
Add the chopped onions and sauté until they turn golden brown, which should take about 5-7 minutes.
Add the chopped tomatoes and cook until they become soft and the oil starts to separate from the mixture, stirring occasionally. This may take around 7-10 minutes.
Stir in the coriander powder, cumin powder, garam masala, and paprika powder (if using). Cook for another 2-3 minutes to allow the spices to blend.
Add the marinated chicken to the pan and cook for about 5-7 minutes, or until the chicken turns white and is partially cooked.
Pour in enough water to cover the chicken. Bring it to a boil, then reduce the heat to low, cover the pan, and let it simmer for about 20-25 minutes or until the chicken is cooked through and tender. Stir occasionally.
Adjust the salt and spices according to your taste. If you prefer a thicker curry, you can let it simmer for a bit longer to reduce the sauce.