To begin, heat 2 tablespoons of olive oil in a deep pot over medium heat and add the lamb shanks, harissa, coriander bunch, and tomatoe to the pot.
With the ingredients in the pot, season the meat with salt, pepper, turmeric, and ginger powder. Now brown the lamb shanks on all sides until they are nicely brown and caramelized.
After browning the lamb shanks, pour the water into the pot and cover it and bring it to a boil. Then, reduce the heat to medium and let it cook for approximately 30 minutes, or until the lamb is halfway done.
At this point, you should notice that the liquid in the pot has reduced by half.
Next, add the vegetables to the pot - carrots, zucchini, potato, cabbage, and chickpeas. Allow them to cook for approximately 40 minutes or until the lamb is fork-tender and the vegetables are cooked through.
As soon as the vegetables have been added to the pot, it's time to prepare the couscous. To start, mix the couscous with the remaining oil and season it with salt. Make sure to add just enough water to wet the couscous without soaking it. Gently sprinkle the grain into a colander in layers, but be careful not to compress it.
Lastly, set the colander on top of the simmering stew and cover it with a lid, allowing the couscous to steam. Keep the couscous steaming until the lamb and the vegetables are cooked through.
Once the couscous is fully cooked, it's important to fluff it with a fork to ensure a light and fluffy texture. Separate any clumps and mix them gently to get a perfect consistency.
To serve, spoon a generous amount of couscous onto each plate and top it with flavourful vegetables and succulent lamb shanks. Finally, garnish with some fresh coriander and serve hot savouring every delicious bite.