Method
Mix the harissa with half the lemon juice, 1 tbsp coriander and some salt and rub it all over the chicken. Lay it flat on a baking sheet and grill for 4-5 minutes on each side or until cooked through.
Meanwhile, put the couscous in a bowl, add a cupful of boiling water, cover and leave for 5 minutes. Mix in some seasoning, the rest of the lemon juice and coriander, the mint and the butter beans.
Serve the chicken with the couscous.