Combine the chicken and all the marinade ingredients and mix thoroughly so its completely covered. Let it rest overnight (6-8 hours) ideally.
Cover the cashews in ¼ cup of boiling hot water and let them sit for 20 minutes. Blend into a smooth cream/paste with the same water you soaked them in.
In a dry fry pan, lightly toast the coriander seeds until fragrant. turn off the heat and add the caraway seeds, let them cool and then pound/grind to a fine powder.
In a heavy bottom pot, add the ghee and let it melt on low heat. Add the whole spices (cinnamon, black cardamom, bay leaf, cloves and peppercorn) and let them sizzle. Add the sugar and let it melt and become caramel-like.
Add the thinly sliced onion, season with salt and let them fry for a while. You want to do this on medium heat so you can get even caramelisation. The onions should reduce, become jammy and develop a deep golden brown colour. Don't rush this step, it should take a good 15-20 minutes. Set aside a tablespoon of the onions for garnish later.
Add the spices (turmeric, chilli, powdered coriander/caraway) and fry until fragrant. Lower the heat and add the marinated chicken and toss it continuously so the yogurt doesnt split/burn. Cover and let it cook until the chicken is tender. If at any point you feel like it sticks to the pot, add spoonfuls of hot water as required and mix nicely. Adjust seasoning (salt/sugar) as needed.
When the chicken is about 95% cooked, add the creamy cashew paste and let it finish cooking. Freshly grate a pinch of nutmeg and keep it covered. Let it rest for atleast 30 minutes before serving.
Garnish with the caramelised onions and serve with rotis/flatbreads.
