Five-spice powder is a pungent seasoning mix used widely in Chinese cooking. It is made of equal parts ground cloves, cinnamon, fennel seed, star anise, and Szechuan peppercorns and lends an irresistible flavor to pork tenderloin.
Preheat oven to 400 degrees. Combine spice powder and salt on a plate; generously coat pork tenderloins. Heat a large ovenproof skillet over medium-high heat, and pour in oil. Add tenderloins; brown well on all sides, about 4 minutes per side.
Transfer to oven, and roast until meat is cooked through, about 15 minutes or until a meat thermometer inserted in the center registers 160 degrees. Remove from oven; let rest 5 minutes before slicing. Serve.