Heat the oil in a large, deep frying pan over a medium heat and brown the chicken thighs all over, about 5 mins. Remove the chicken from the pan, leaving behind the oil. Reduce the heat to medium-low, then add the onions and fry for 10-12 mins until softened but not golden. Stir in the ginger and garlic, and cook for a minute before stirring in the cumin. Cook for another minute.

Tip in the sweet potatoes, stir to coat, then fry for a few minutes until starting to soften. Stir in the peanut butter and pour in the chicken stock and chopped tomatoes. Swill out the can with a splash of water and pour that in, too. Mix in the frozen peppers, return the chicken to the pan, then cook, uncovered, for 25-35 mins until the chicken is cooked through and the sauce has thickened. Stir regularly to stop the sauce from catching. Scatter over the coriander and peanuts. Can be frozen for up to three months and reheated from frozen, or defrost in the fridge overnight before reheating. Ensure it is piping hot throughout before serving.