Slice pork crosswise into ¾-inch-thick medallions, leaving narrow "tail" portion 1-inch-thick. Press each medallion with heel of your hand to flatten slightly. Season both sides with salt and pepper, and rub surface with about 1 teaspoon of the olive oil so all surfaces are lightly coated. Set aside.
In a medium bowl, combine the mango, cilantro, green parts of the green onion (reserve white parts), lime zest, lime juice and red pepper. Add remaining 1 teaspoon olive oil, and salt to taste.
Heat a medium skillet (preferably cast iron or non-stick) over medium-high heat. When hot, sauté the pork medallions in a single layer (do this in batches if necessary), until browned and just cooked through, 2 to 3 minutes per side. (You may cut one medallion to check for doneness; there should be a trace of pink.) Transfer pork to a plate to rest.
Return the skillet to medium heat, add the reserved white scallions, and sauté for 1 minute. Add the orange juice, scrape bottom of skillet with a wooden spoon, and bring to a boil. Boil until slightly syrupy, another minute. Return the pork to the skillet, turning to reheat and coat with glaze. Serve immediately, drizzling any remaining glaze over the top and putting the salsa on the side.