Preheat the oven to 375℉. Remove the pork tenderloin from the fridge 30 minutes in advance. Season with Italian seasoning, salt, and pepper.
Heat the cast iron pan to medium high heat. Add olive oil to the pan. Sear the pork tenderloin on each side for 60-90 seconds.
Place the cast iron in the oven and bake for 15-20 minutes or until the tenderloin reaches 140℉.
Remove the tenderloin from the pan and rest on a cutting board for 10 minutes. Then slice into ¾ inch slices.
Place the cast iron pan on the stovetop and bring to medium-low heat. Add the butter and garlic to the pan. Once the butter finishes foaming, add the white wine. Bring to a simmer and reduce by half. Pour the sauce over the sliced pork tenderloin and serve.
Notes
Take the pork tenderloin out of the refrigerator for 15-30 minutes to bring it closer to room temperature. This will help keep the pork tender and moist and avoid drying it out in the oven.
Dry the pork with a paper towel before seasoning.
I typically sear the pork on "3" sides even though it's a circle. On the 3rd side, I sear for about 30 seconds and then place in the oven.