This recipe was inspired by Moroccan crevettes pil pil, a stewy, fragrant shrimp dish that is rich in fruity olive oil. The warm spices, smoky harissa, sweet-tart tomatoes and lots of garlic are a wonderful complement to plump, briny shrimp. Here, to round out the meal, we add pearl couscous. First, we toast the couscous in olive oil to enhance its nutty taste, then simmer it in the fragrant sauce. Be sure to use pearl couscous, also known as Israeli couscous or ptitim. A type of semolina pasta prized for its tender-chewy texture, it is more substantial than regular couscous. Before adding the caraway seeds to the pan, lightly crush them with a mortar and pestle or a heavy skillet.