Rinse the basmati rice in chilly water until the water becomes clear. Immerse the rice in water for half an hour, then drain it thoroughly.
In a spacious bowl, infuse the chicken with yogurt, ginger, garlic, and half of the biryani masala powder. Allow it to marinate for a minimum of one hour.
Warm oil in a substantial and deep pan over medium heat. Introduce the thinly sliced onions and cook them until they attain a golden brown hue. Set aside half of the onions for garnishing. Add the cumin seeds, cardamom pods, cloves, cinnamon sticks, and bay leaf to the pan. Stir them for a minute until their aroma fills the air.
Incorporate the marinated chicken into the pan and cook it until it turns a rich brown on all sides. Include the chopped tomatoes, the remaining biryani masala powder, turmeric powder, chili powder, and salt. Cook for approximately five minutes, until the tomatoes turn tender.
Gently add the soaked and drained basmati rice to the pan, ensuring it mingles harmoniously with the chicken and spices.
Pour an ample amount of water into the pan, ensuring it covers the rice by approximately an inch. Bring the mixture to a boil, then reduce the heat to a low setting and securely cover the pan with a well-fitted lid. Allow it to cook for a span of 20-25 minutes or until the rice becomes tender and the liquid is fully absorbed.
Remove the pan from heat and allow the biryani to rest for ten minutes. Use a fork to fluff the rice, and garnish it with the reserved fried onions and fresh cilantro leaves.