Pre-heat oven to 400℉.

Combine garlic powder, thyme, rosemary, oregano, salt and pepper in a small bowl to create dry rub mixture.

Pat dry pork tenderloins and rub them with 2 tbsp olive oil. Evenly coat pork tenderloins with dry rub mixture. Press mixture onto pork on all sides.

Heat cast iron skillet with 1 tbsp olive oil under medium high heat.

Once oil is heated, sear pork tenderloins on one side for ~1 minute or until golden brown, then turn and sear the other sides until golden brown. This should only take a few minutes.

Bring pork and cast iron into the oven and roast for 20 minutes, flipping halfway through.

Check temperature at the thickest part of the pork. If it reaches 145℉, remove from oven. If not, continue cooking until it reaches 145℉. For largest pieces of pork, it may need more time in the oven.

Remove pork from oven and place it on a plate then covered with aluminum foil. Let it sit for 5 minutes.

Heat cast iron skillet (along with drippings from roasting the pork) on stove top and add butter.

Once butter is melted, add flour and stir, scrapping up all the drippings and herbs that was on the skillet.

Add milk and bring to a boil, whisking continuously to remove any clumps. Once gravy is smooth and thickened, remove from heat. Add more milk at any point to thin out gravy as needed.

Slice pork tenderloin and serve with gravy and garnish with fresh parsley. Enjoy!