Couscous is actually not a grain, but a finely milled pasta made from semolina: it now comes in a quick-cooking form that does not require the traditional steaming. All the elements of this Asian-inspired salad, which is perfect for a summer dinner, are united by the flavor of curry. Harissa is sold in tubes at Middle Eastern groceries and many specialty food stores. It is a paste made from hot chilies flavored with coriander, caraway, garlic, and salt.