Cover potatoes with 2 inches water in a pot. Add 1 tablespoon salt. Bring to a boil, then reduce to a simmer and cook until knife-tender, about 8 minutes. Drain.
Heat oil in a large skillet (preferably cast-iron) over medium-high. Add potatoes and cook, stirring occasionally, until golden and crisp, about 10 minutes. Stir in pimenton and two-thirds of scallions and cook 30 seconds more. Season with salt, sprinkle with remaining scallions, and serve.