Heat 2 tablespoons oil in a heavy, wide pan. Add the sliced onions. Fry on medium heat for 5-7 minutes until the onions turn soft and golden but not too dark.
Then, add the cashews, green chillies and cumin seeds. Fry everything for 2 more minutes until cashews look slightly toasted. Let this mixture cool slightly, then transfer to a blender jar and grind using as little water as possible into a smooth paste. Tip: Blending while slightly warm helps achieve a silkier texture. In the same pan, add the remaining oil. Add bay leaf, cinnamon stick, green cardamom. Let crackle gently for 15-20 seconds to release their aroma.
Add the prepared onion–cashew paste to the pan. Stir in coriander powder and white pepper powder.Add a small splash of water to the blender jar to loosen the stuck onion mixture. Pour this liquid into the pan. Cook on low to medium heat for 3 to 4 minutes, while stirring often, until the masala thickens and looks glossy.
Add the sauteed chicken along with any juices. Mix well to coat the chicken in the masala. Cook on medium heat for a 3-4 minutes until the chicken starts to firm up and absorb the flavors.
Lower the heat to medium and add the whisked yogurt to the pan next.Add salt As soon as you add the yogurt, stir continuously for 2-3 minutes to prevent the yogurt from curdling.
Once the yogurt is warmed through, cover the pot with lid. Cover and cook on low heat for 7-10 minutes or until the chicken is tender and fully cooked. Stir occasionally to prevent sticking.Note - If you are using bone in chicken, let cook covered for 18-20 minutes or until chicken is cooked through. There is no need to add any water- the water content of yogurt and the chicken is enough to make a gravy. Once the chicken is cooked. Stir in the heavy cream. Add freshly ground black pepper, cardamom powder, and freshly ground nutmeg. Simmer uncovered for a 3-4 minutes until the sauce reaches your desired consistency.
Taste and adjust seasoning.Adjust salt as needed. The sauce should have a warm, peppery kick balanced with creamy notes. Add more black pepper if you like it bold.
Garnish with fresh cilantro and let the curry rest for a few minutes before serving. Tip: the pepper flavor deepens as it sits, making leftovers even more delicious.