Method

Preheat oven to 375°F.
Let the tenderloin sit on the kitchen counter for about 20 minutes so it loses it’s chill.
Season with olive oil, salt and pepper.
In a heavy skillet over medium-high heat, sear all sides of the tenderloin for about 3 minutes each. Resist the urge to move the tenderloin while it’s searing.
Place the tenderloin and pan in the oven. After 4 minutes, brush with olive oil and sprinkle with chopped rosemary.
Let cook for another 4 minutes for medium-rare; 5 minutes for medium-well, and 6 minutes for medium.
Remove from the oven and transfer to a cutting board. Let rest for 5 minutes before slicing.
Serve hot.