Couscous typically plays a supporting role to tagines or other stews, but here we transform the tiny pasta into crisp, pan-fried cakes that can be the center of a meal. Chopped olives and harissa, a North African spiced pepper paste and a must-have ingredient in our pantry, lend a decidedly Mediterranean flavor. And to add a little gooey richness, we also mix in some shredded mozzarella cheese. Serve the cakes atop a bed of greens or sandwich them between buns.