How to Make It
In a medium saucepan, cover the potatoes with water and bring to a boil. Add a large pinch of salt and boil over moderately high heat until just tender, about 15 minutes. Drain the potatoes and let cool, then quarter them.
Meanwhile, in a small saucepan of boiling salted water, cook the corn until crisp-tender, about 3 minutes. Drain and pat dry with paper towels.
In a large skillet, heat the oil. Add the potatoes and cook over moderately high heat until browned on the bottom, about 5 minutes. Add the corn and cook until lightly toasted, about 3 minutes. Season with salt and pepper. Add the spinach and cook, tossing, until wilted, about 1 minute. Remove from the heat. Sprinkle the Manchego over the potatoes and stir twice, then transfer to a platter and serve.