Pre-heat oven to 160°C (140°C fan-forced).
Heat half the oil in a large pan and add shanks cooking over a medium-high heat until seared all over. Set aside. Wipe pan out if required.
Heat remaining oil and cook the onion and garlic for 3-4 minutes until tender. Stir in spices and cook until fragrant. Add tomato paste and cook a further minute.
Pour the stock into the pot with the lamb shanks and cinnamon sticks, bring to the boil, cover and transfer to the oven. Cook for 1 hour, then add the orange and dates to the pot. Return to the oven a further hour, or until lamb is easily pulled away from the bone.
Remove shanks from the pot and place pot over a cooktop and rapidly boil for 3-4 minutes to reduce liquid slightly. Return shanks to the pot, stir in coriander and season to taste.
Meanwhile; place couscous into a large bowl and pour over the boiling water with the oil. Stir and allow to sit covered for 2 minutes. Stir in chopped herbs and season to taste. Serve lamb shanks with couscous, yoghurt, harissa and flaked almonds.