Cook pierogies and beans in boiling water according to pierogi package directions. Drain pierogi and beans. Set aside; keep warm.
Meanwhile, slice pork into 1/2-inch thick medallions. Gently pound slices by hand to 1/4-inch thickness; lightly sprinkle with salt and black pepper. Heat oil in large skillet over medium heat. Add pork. Cook 2 to 3 minutes on each side or until no pink remains. Set aside; keep warm.
Drain fat from skillet. Add balsamic vinegar to hot skillet. Cook, uncovered, 1 minute or until reduced by half. To serve, drizzle balsamic reduction over pork, pierogi, and beans; garnish with rosemary.