Step 1

Preheat oven to 350 degrees.

Step 2

Rub the olive oil over all sides of the pork.

Step 3

Sprinkle the pork evenly on both sides with the salt, pepper, garlic and rosemary (and orange zest, if you are using it).

Step 4

Preheat an oven-safe grill pan on the stovetop at medium-high heat.

Step 5

Place the pork tenderloin on the hot pan, and sear all four sides for about 2 minutes each.

Step 6

Transfer the pan with the pork into the preheated oven, and bake for about 20 to 25 minutes

Step 7

Take the tenderloin out of the over, and let it rest for about 10 minutes before slicing and serving.