1. In an iron skillet or oven safe skillet, pour in 2 tablespoons of the olive oil and turn the heat to medium. Add the chopped white parts of the scallions and the garlic. Saute for 2 minutes until softened.
2. Add the diced potato, turn the heat to medium-low and cook until soft, about 10 to 15 minutes. Add the corn kernels, season with salt and pepper, and cook for 1 minute if corn is frozen and 3 minutes if fresh.
3. Preheat the broiler.
4. In a large bowl, whisk together the eggs, green parts of the scallion and mozzarella. Pour in the potato mixture, and stir until well combined. Wipe out the skillet.
5. Pour the last tablespoon of the oil into the now clean skillet. Turn the heat to medium-high. Dump in the egg mixture and cook for 6 minutes, shaking the pan every 1 minute or so to keep it from sticking.
6. Then place the skillet underneath the broiler and cook for 2 to 3 minutes, or until the top is golden brown. Remove from the broiler, and slide onto a plate. Season with salt and pepper, carve like a pie, and eat.