Step 1

Preheat oven to 350°F. Rinse and pat dry pork loin, and then season with salt and pepper.

Step 2

MAKE THE PORK LOIN: Heat a large oven-safe skillet on medium-high heat. Add oil and then sear the pork loin on all sides until a crust forms, about 1 minute per side. Remove pork loin from the pan and set it aside. Coat the pork loin with dried herbs by patting it onto the loin.

Step 3

Turn off heat and remove pan from the heat. In same hot pan add butter, garlic, Worcestershire sauce, and mustard. Stir the sauce until the butter is completely melted. Place the pork loin back in the skillet and spoon some sauce over the pork loin.

Step 4

Cover the pork loin with foil and roast for 30 minutes. Remove foil, spoon some more sauce over the loin and cook for about another 30 minutes or until the interior temperature reaches about 140°F.

Step 5

Remove cooked pork loin skillet from oven. Remove the pork loin from the skillet and cover the pork with foil to let it rest for about 15 minutes (make the gravy while the pork is resting). (Don't clean the skillet, you'll need it for the next step in making the gravy.)

Step 6

MAKE THE GRAVY: Heat the same skillet with the pork drippings on medium-high heat.  Skim off any crust chunks in the drippings. Add onions and cook until golden and caramelized, about 5 minutes.

Step 7

Whisk in the flour, whisking to remove lumps. Gradually whisk in the broth until incorporated and well combined. Season with salt and pepper, to taste (the saltiness and flavors will concentrate some when it reduces down).

Step 8

Reduce heat to medium, stirring often, simmer until thickened, about 5 minutes depending on your preferred thickness. Check for seasoning and salt again if needed. Slice pork loin and serve hot with the onion gravy.