Place the chicken breasts on a chopping board and cover loosely with a sheet of cling film. Using a rolling pin or a meat mallet, pound them to flatten the thickest parts so that the breasts are relatively even in thickness all over.
Mix the oil, cumin, garlic, half the lemon juice and some black pepper in a bowl and swish the chicken around to coat it completely. Cover and leave the chicken in the fridge to marinate for 10 minutes, if you have time.
Meanwhile, to make the salad, mix together the leaves, tomato, carrot and mint. Set aside.
Heat a frying pan until very hot. Lift the chicken and allow the excess marinade to drip off. Cook in the hot pan on a high heat for 2 minutes on each side.
Add the stock – it will bubble up rapidly. Reduce the heat to medium and partly cover. Cook the chicken for 5 more minutes, or until cooked through (you’ll need to remove it from the pan and cut into it to make sure it’s cooked). Put the cooked chicken on a warm plate and scrape all the juices out on the top.
To serve, heat the flatbreads in the frying pan over a medium-high heat for a minute on either side, until they are warmed through and a little toasty. Place the flatbreads on two plates and spread each with some hummus. Slice the chicken into thin strips and divide between the two flatbreads. Top with the salad, hot chilli sauce (or other sauce if you prefer) and a squeeze of lemon juice. Roll up and serve.