Preheat your oven to 400 degrees F (200 degrees C) and position the rack in the middle.

Trim any excess fat and silver skin from the tenderloin. Pat it dry with paper towels to ensure a good sear. Pierce the tenderloin all over with a fork to help the seasoning penetrate and keep the meat juicy.

Rub the tenderloin with 1 tablespoon of oil. Combine the kosher salt, black pepper, smoked paprika, Italian seasoning, garlic powder, ground coriander, and dried rosemary in a small bowl. Sprinkle the seasoning mixture over the tenderloin, and use your hands to rub the spices into the meat until evenly coated.

Heat the remaining tablespoon of oil in a large oven-safe skillet over medium-high heat. Cast iron or a Dutch oven works best. Once the oil is hot, add the pork tenderloin and sear it on all sides until browned, about 6 minutes total.

Transfer the skillet to the preheated oven and roast until the internal temperature reaches 145 degrees F, about 15-20 minutes depending on the size of the tenderloin.

Remove the skillet from the oven and let the tenderloin rest for 5-10 minutes before slicing. This allows the juices to redistribute for maximum flavor and tenderness. Slice into medallions and serve.