Start by trussing the pork loin. See the video below on who to do this.
Place the trussed pork loin on a sheet tray with a rack and generously season it on all sides with salt and pepper.
Put the pork on the rack in the refrigerator uncovered for 24 hours and up to 48 hours. This process is known as dry brining.
Make the herb butter by whipping the softened unsalted butter in a stand mixer with the paddle attachment on high speed for 5 to 7 minutes or until it becomes light and fluffy.
Turn the speed to low and add garlic, thyme, rosemary, salt, and pepper until combined. Set it aside.
In a large 12” inch sauté pan with olive oil, heat it over high heat until it begins to smoke.
Place the pre-seasoned pork into the pan fat cap side down turn the heat down to medium, and sear for 3-4 minutes or until well browned.
Give the pork a quarter turn and cook for 2 to 3 minutes or until well browned. Repeat the process on the direct other side until well browned.
Turn the pork to seared fat cap side up turn the heat down to low, and cook for 1 minute.
Add in ½ of the herb butter.
Once it’s melted, baste the pork with a large spoon for 3 to 4 minutes.
Place the pork on the middle rack in the oven at 300° and cook for 32-35 minutes or until it reaches an internal temperature of 135°. This will render a medium internal temperature.
Once it’s done cooking, set the pork on a plate or cutting board and rest for 15 minutes.
While it’s resting, drain half the fat from the pan and return the pan to a burner over medium heat.
Stir in the shallot and cook sauté for 2 to 3 minutes or until lightly browned.
Add the wine and cook until 2 to 3 tablespoons are remaining.
Deglaze with the beef stock and cook over high heat for 2-4 minutes or until the amount of liquid is reduced by 2/3. It should be thicker, like a gravy.
Finish by stirring in the mustard, dried cherries, 1 tablespoon of the herb butter, salt and pepper.
Slice the pork and serve with the sauce.
Notes
Make-Ahead: While this is meant to be eaten as soon as it comes out of the oven and is sliced, you can make this 30 minutes ahead of time while keeping it warm in an oven at 165°. You can only do this if you prefer the pork loin to be well done internally.How to Store: Place covered in the refrigerator for up to 4 days. This will freeze covered for up to 2 months. Thaw in the refrigerator for one day before reheating.How to Reheat: Please note that reheating pork will cause it to overcook immediately. The best way to heat it is in a pan or a sheet tray lined with parchment paper in the oven at 350° for 6-8 minutes or until warm. Heat the sauce separately in a small saucepot over low heat until warm.It’s important to rest this pork, or any protein, after cooking to allow for the juices to soak back into it, making it more flavorful.If the herbs and spices start to burn in the pan, then turn the heat down more. It will just take a few more minutes to cook.To serve the pork loin at a medium internal temperature, you will want to take it out of the oven when it reaches 135°. With carry-over cooking, the pork will advance in temperature while resting at or above 140° to 145°, making it a perfect medium internal temperature.You will have some herb butter leftover to use in another recipe later. The butter freezes well.