We got an education in couscous in Tunisia, including a lesson from Amel Cherif, a home cook who showed us the basics of making couscous light and flavorful at her apartment on the outskirts of Tunis. For our version, we use an 8-quart pot fitted with a stackable steamer insert that sits on top. If you don’t own one, a large pot and a folding steamer basket worked well, too. Whisking the liquid from the stew into the steamed couscous is a key step, deeply flavoring the grain-like pasta and helping it stay light, fluffy and distinct. We especially liked this dish made with our homemade harissa. Among store-bought brands, we preferred DEA, which is sold in a tube and in cans. We start the recipe using 1/4 cup of harissa to flavor the stew, then finish by mixing another 1/2 cup into the stew liquid just before whisking it with the steamed couscous. If your harissa is particularly spicy or you prefer less heat, reduce the second addition of harissa.