Directions

1. In a large cast-iron or other ovenproof skillet, cook the spinach in 1/4 cup water over medium heat for 3-4 minutes or until wilted; drain well. In a large bowl, combine the spinach, artichokes, Parmesan cheese and rosemary; set aside.
2. Cut a lengthwise slit down center of tenderloin to within 1/2 in. of bottom. Open meat so it lies flat; cover with plastic wrap. Flatten to 1/4-in. thickness; remove plastic. Sprinkle meat with 1/4 teaspoon salt; top with spinach mixture.
3. Close meat; tie with kitchen string and secure ends with toothpicks. Sprinkle with pepper and remaining salt. Place in skillet. Bake at 425° for 15 minutes.
4. Meanwhile, in a small saucepan, combine the sauce ingredients. Bring to a boil over medium heat. Reduce heat; simmer, uncovered, for 15 minutes. Pour over the meat. Bake until a thermometer reads 145°, 10 minutes longer. Let stand for 10 minutes before slicing. Discard toothpicks.