Heat the olive oil in a large saucepan over a moderate heat.
Cook the onion, garlic and chilli for 4-5 minutes or until soft.
Add the chicken and stir over the heat to sear. Add the turmeric and cumin and cook for another minute.
Add the tomato, lentils, pearl barley and stock to the saucepan and bring to the boil. Reduce the heat to moderate and simmer for 30 minutes or until the lentils are cooked. Season the soup to taste with salt and pepper.
Stir through the lime juice. Serve with a dollop of yoghurt and fresh cilantro.