Mix the spices together in a bowl. Heat the olive oil and fry the onion until softened. Add in the ginger and garlic and fry for a further minute.
Next add the spices and fry for one minute and then throw in the chicken and cook until just browned on the outside. Transfer everything to a Crockpot or slow cooker and add in the water, tomato and cream.
Cook on full power for around two hours and then reduce to low for the remaining time (I usually cook for around 6-8 hours in total), stirring every now and again. Serve with rice or bread.