Preheat the slow cooker on high. Lightly rinse or wipe the chicken drumsticks and pat dry on kitchen roll. Heat the oil and butter in a frying pan, brown the drumsticks on all sides, drain and place in the cooking pot.
Add the onion, garlic and chilli to the frying pan and saute for 5 minutes or until softened. Sprinkle in the flour and cook for 2 minutes, then take off the heat.
Blend the tomato puree with a tablespoon of the stock and gradually stir into the pan with the remaining stock and the chopped tomatoes.
Add the chocolate with seasoning and bring to the boil Cook, stirring until the sauce has thickened slightly, then pour over the drumsticks. Cook on high for 3-5 hours.
Remove from the cooker, adjust the seasoning of the sauce then pour over the chicken. Sprinkle with the sesame seeds, garnish with lime wedges and serve with freshly cooked rice and a green salad.
I served my chicken with couscous and roasted peppers, courgettes and onions.