In a large bowl, combine the chicken pieces with yogurt, ginger-garlic paste, lemon juice, red chili powder, garam masala, salt, and melted butter. Mix well to coat the chicken evenly. Cover and let it marinate in the refrigerator for at least 30 minutes, or up to overnight for deeper flavor.

In a large pot, bring 4 cups of water to a boil. Add the soaked and drained basmati rice, bay leaf, cardamom pods, cloves, cinnamon stick, and salt. Stir gently.

Cook the rice uncovered on medium heat for about 8-10 minutes, or until the rice is about 70% cooked. It should still have a slight bite to it. Drain the rice and set aside.

In a heavy-bottomed pan, heat 2 tbsp of oil over medium heat. Add the sliced onions and fry until they are golden brown and caramelized, about 10-15 minutes. Stir occasionally to prevent burning.

Add the marinated chicken to the pan and cook on medium-high heat for about 10-15 minutes, stirring occasionally, until the chicken is cooked through and the oil begins to separate from the sauce.

Reduce the heat to low. Spread half of the cooked rice over the chicken in the pan. Drizzle half of the saffron milk over the rice and sprinkle half of the chopped cilantro and mint.

Add the remaining rice on top, followed by the rest of the saffron milk and herbs. Cover the pan with a tight-fitting lid to trap the steam.

Cook on low heat for 20-25 minutes. This allows the flavors to meld and the rice to finish cooking.

Once cooked, gently fluff the biryani with a fork to mix the layers without breaking the rice. Serve hot with raita or salad on the side.