Heat the oil in a large casserole dish or large frying pan with deep sides.
Add the onion, cinnamon and chilli and cook until the onions have softened.
Then add the cubed chicken seasoned with pepper and continue frying until the chicken turns white. Add the potatoes, curry paste, coconut milk, fish sauce, lime leaves and 200ml of water. Bring to the boil, then reduce heat and simmer for 15 minutes. Stir in the kale and cook for a further 5 minutes. Serve with chopped, unsalted peanuts.