Tip the couscous into an ovenproof dish. Stir ½ teaspoon salt into the measurement water and pour over the couscous. Stir once to make sure all the grains are submerged in the water, then cover with a clean tea towel and leave to stand for about 10-15 minutes. Rake a fork through the couscous to break up the grains. Then, using your fingers, rub the oil into the grains until light, airy and any lumps are broken up.
Stir the preserved lemon rind, feta and dried mint through the couscous until thoroughly mixed, then season with salt and pepper. Cover with a piece of damp greaseproof paper and place in a preheated oven, 180°C (350°F), Gas Mark 4, for about 15–20 minutes until heated through. Garnish with the fresh mint. Serve with tagines or grilled meat and poultry.