Begin by gathering all your ingredients for the Keto Pork Tenderloin. Rinse the pork tenderloin under cold water and pat it dry with paper towels. Season generously with sea salt and freshly cracked black pepper, ensuring even coverage to enhance the meat's flavor. Set aside while preparing the garlic herb stuffing.

Using a fork, poke several holes in the pork tenderloin. This will allow the savory mixture of minced garlic and herbs to infuse into the meat as it cooks. Take the minced Italian herbs and press them deeply into the tenderloin’s surface, particularly in the holes you've made, to ensure that every bite is packed with flavor.

In a mixing bowl, combine the melted unsalted butter with minced herbs, garlic salt, and onion powder. Stir thoroughly until the mixture is well blended, creating a luscious garlic herb butter that will envelop the pork tenderloin. This rich concoction will not only flavor the pork but also create a deliciously decadent drizzle for serving.

Preheat your oven to 425°F (220°C). While the oven is warming up, you’ll ensure that the pork gets that perfect sear. Proper preheating is crucial for achieving that crispy outer layer that locks in all the juicy goodness of the Keto Pork Tenderloin.

In a cast-iron skillet, heat 2 tablespoons of avocado oil over medium-high heat. Once the oil shimmers, add the seasoned pork tenderloin to the pan. Sear on one side for about 3 minutes or until a beautifully browned crust forms. Carefully flip the pork and repeat on the other side, ensuring an even sear for a delectable flavor throughout.

After searing, transfer the skillet with the pork tenderloin directly to your preheated oven. Bake for 20-25 minutes, or until the internal temperature reaches 145°F (63°C). The pork should be juicy and tender, with a hint of pink in the center, signaling its perfect doneness and mouthwatering texture.

Once baked, remove the skillet from the oven and let the pork tenderloin rest for 3-5 minutes. This allows the juices to redistribute, ensuring each slice remains moist. Slice the tenderloin into medallions and drizzle generously with your prepared garlic herb butter, elevating this dish to an irresistible treat for your dinner table.