Add the chicken, onion, garlic, ginger, tomato passata, tomato paste, all the spices and honey into the slow cooker.
Give everything a good stir, then add the butter on top.
Put the lid on and cook on low for 5 to 6 hours or high for 3 to 4 hours, until the chicken is tender and cooked through.
Stir in the double cream and chopped coriander and cook for another 10 to 15 minutes until heated through.
Serve with fluffy rice and naan bread, and enjoy!