In a large bowl, mix spices, tomato paste, coconut milk, yogurt and cream.
Spray the inside of your slow cooker with cooking spray. Add onion to slow cooker, then chicken. Pour sauce over chicken. Add the butter on top of sauce, cover and cook on low for 6 to 8 hours.
Serve with white rice and naan.
Recipe by Food Fun Family at https://foodfunfamily.com/slow-cooker-butter-chicken/