1. Heat oil in a medium skillet over high heat. Once oil is hot, add eggs. Decrease heat to medium and fry eggs until whites are firm and yolks are set but slightly runny, 1-2 minutes. Season with salt and pepper.
2. Meanwhile, toast bread. Spread 2 slices of toast with harissa, adding more if extra spice is desired. Sprinkle cilantro leaves over harissa. Spread remaining slices of toast with yogurt and sprinkle with cumin. Place 1 tomato slice and 1 fried egg on each yogurt-topped slice of toast, then top each of the sandwiches with a slice of harissa-cilantro toast.