1Cut tenderloin into 4 pieces; pound until 1/3-inch thick.
Heat oil in a large skillet and brown pork for 3 minutes per side; remove and set aside.
2Combine orange juice and cornstarch; add to the skillet along with marmalade, lemon juice, horseradish, cinnamon and salt and bring to a boil.
Reduce heat; cook and stir until the sauce thickens, about 2 minutes.
3Return pork to skillet; cover and cook 8 to 10 minutes or until pork is done.
Serve over noodles; garnish with mandarin oranges.