Step 1 For the yoghurt, mix all ingredients in a small bowl and set aside.
Step 2 Steam carrots, covered, over boiling water for 3-5 minutes until just tender.
Step 3 Meanwhile, place couscous in a heatproof bowl and pour over 1 1/2 cups (375ml) of boiling water. Cover and stand for 5 minutes. Uncover, fluff with a fork, then add chickpeas and carrots.
Step 4 For the dressing, whisk sumac, lemon juice and olive oil in a bowl.
Step 5 Add to the couscous and toss together.
Step 6 Serve the chickpea and carrot couscous with the minted yoghurt. Garnish with mint leaves.