If the chicken is not ready cooked, fry in a pan until cooked and then set aside
Whisk together the lemon zest and juice and olive oil, season and pour over the chicken. Cover and leave to marinade in the fridge for at least 10 minutes.
Meanwhile put the couscous in a bowl and pour over the hot stock. Leave until the liquid is absorbed. Fluff with a fork.
Fold in the tomatoes, nuts, mint, lemony marinade and chicken. Serve.