You may have seen recipes where ground coffee was used as a rub component. It adds a pleasant, slightly bitter and full flavour. In this chicken thigh fillet recipe, the coffee combined with the curry powder will have the same effect. You could, of course, decide to leave the chicken thigh fillets whole and grill them after rubbing them with the curry-coffee mixture. In this case, you will need to observe a slightly longer preparation time to make sure that the meat is done. You could always measure the core temperature and in this case, you should aim for a temperature of at least 70 °C.