Place all the ingredients except butter, yogurt and coriander leaves in slow cooker and let it cook for 4-5 hrs. on low until chicken becomes tender and all the ingredients incorporate well to form a thick gravy.
After that add yogurt and cook for 3-4 min on medium heat.
Take out the chicken makhani in serving bowl with lid and then top with butter and coriander leaves, immediately cover the bowl with lid so that all steam remain inside and butter melts completely.
Serve the delicious chicken makhani with naan.