Red bell pepper and scallions add crunch and color to this full-flavored hash. Steak, chicken or turkey could be substituted for the pork, if you like.
Sprinkle flour over pork and turn to coat both sides. Heat 2 teaspoons oil in a large nonstick skillet over medium-high heat. Spread the pork evenly in the pan and cook until lightly browned on one side, 1 to 2 minutes. Continue cooking, stirring occasionally, until evenly browned, 1 to 2 minutes more. Transfer the pork to a plate and cover with foil to keep warm.
Heat the remaining 2 teaspoons oil in the pan over medium-high heat. Add onion and cook, stirring often, until starting to brown, 1 to 3 minutes. Add potatoes, bell pepper, paprika, garlic powder, rosemary, salt and pepper. Cook, stirring frequently, until the potatoes are browned and crispy in spots, 4 to 8 minutes. Add the pork and scallions and cook, stirring often, until the pork is heated through, about 2 minutes. Stir in vinegar.