Heat a medium skillet over medium-high until very hot (a splash of water should instantly sizzle away). Add enough oil to generously coat the bottom of the pan, then add the cauliflower.
Cook, stirring occasionally, until browned and tender, about 10 minutes.
Add the chickpeas, harissa, allspice, turmeric, salt, and pepper. Cook until the spices are aromatic and the harissa caramelizes, about 1 minute.
Add the broth, taste and adjust seasoning as needed, and bring to a simmer. Add the couscous, and stir well.
Cover, turn off the burner, and steam until tender, about 10 minutes.
Stir to fluff, crumble over the feta, and serve.
