Flatten the pork tenderloin slices slightly, and set aside. In a bowl, mix together the lime zest, olive oil, cumin, salt, crushed red pepper, and garlic. Reserve the lime juice. Rub the seasoning mixture onto both sides of the pork slices.
Spray a heavy skillet or ridged grill pan with cooking spray, and place over medium heat. Pan-fry the pork slices until browned on both sides, 6 to 7 minutes per side. After you turn the meat over, pour the reserved lime juice over the meat and continue cooking until no longer pink in the center. Serve hot, topped with pan juices.