Bring the stock to the boil with the cider vinegar and mint. Add the chicken, cover and simmer for approx. 20 mins. Add the beans, continue to simmer for approx. 15 mins., add the broccoli for the final 5 mins. Remove the chicken, peel away the skin, roughly shred the meat using two forks. Drain the beans and broccoli, retain the stock and pour back into the pan, reduce to approx. 100 ml.
Cook the lentils (covered) in boiling water for approx. 20 mins. until soft, drain and set aside.
Heat the oil in a non-stick frying pan. Add the onions, sauté briefly, add the beans and broccoli, continue to cook for approx. 5 mins., season with salt.
Whisk together the vinegar, oil and reduced stock (100 ml), season. Add the herbs along with the lentils, chicken and vegetables, mix and plate up.