Combine the ingredients for the dressing in a small glass jar. Shake well, taste (it should be fairly tart to offset the sweetness of the mango) adjust seasoning if necessary, then set aside.

In a medium saucepan bring the water, chicken stock and barley the boil. Lower the heat to a steady simmer, use a spoon to skim off any foam, and simmer for 30-35 minutes, or until the barley is chewy but tender. Drain and rinse quickly under cold water, then set aside to cool.

Use paper towel to pat the chicken breasts dry, then season well with salt and pepper. Heat the oil in a large frying pan over medium heat, and when hot add the chicken breasts to the pan. Cook for 4 minutes each side, or until cooked through (see note) then remove from the pan, cover loosely with tin foil and allow to rest for 5 minutes.

Meanwhile, divide the barley between four plates. Top with salad leaves, cucumber and onion. Slice the cheeks of the mangos away from the stone, then using a small knife cut the flesh into squares. Use a large serving spoon to remove the mango flesh from the skin and add to the salads.

Thickly slice the chicken against the grain and divide between the plates. Top each salad with some fresh mint leaves and crumble over the feta. Pour over plenty of dressing, season with a little salt and pepper and serve immediately.