Heat the oil in a large pan. Add the onion and carrots, and cook for 5 minutes until soft. Add the garlic and harissa spices and cook for a further minute. Stir in the pearl barley, chopped tomatoes and 1.3 litres cold water.
Bring to the boil then simmer for 15 minutes. Add the chickpeas to the pan with the dried apricots, leftover roast chicken and chopped parsley. Cook for 10 minutes. Serve with extra parsley to garnish.