Place the semolina in a large bowl. Gradually drizzle in 1¼ to 1½ cups water, rubbing with your hands to form small, even granules. Add the oil and continue rubbing until the grains are light and separate. Season with salt and pepper.
Transfer to a couscous steamer insert set over simmering water. Steam for 45 minutes, stirring once or twice to break up any clumps.
Return the couscous to the bowl. Gradually mix in 2 cups of water. Cover with a kitchen towel and let rest for 15 minutes. Fluff and break up any clumps, then return to the steamer.
Meanwhile, heat the oil in a large pot over medium heat. Add the paprika and cook, stirring, until fragrant and slightly darkened, about 2 minutes. Stir in the tomato paste and cook for 1 minute. Add 1 cup water to loosen.
Add the carrots and chickpeas and cook for 5 minutes. Add the onion, cabbage, squash, celery, potatoes, chicken drumsticks, hawaij, salt, pepper and bouillon powder. Pour in enough water to cover. Bring to a boil, then reduce to a gentle simmer.
Set the couscous steamer over the pot and steam for 40 to 45 minutes, until the vegetables are tender and the chicken is cooked through.
Transfer the couscous to a large bowl. Season lightly with additional salt and pepper. Spoon ½ to ¾ cup of the soup’s surface oil and broth over the couscous, or to taste, and toss gently to coat.
Serve in a wide bowl, with the chicken, vegetables and broth alongside.