Remove the 1 ½ lb pork tenderloin silver skin trimmed from the fridge 15–20 minutes before cooking to take the chill off. Pat it completely dry with paper towels — this is key for a good sear. If needed, trim any silver skin (the thin, shiny membrane) with a knife.

In a mixing bowl, mix together the 1 tsp kosher salt, ½ tsp black pepper freshly ground, 1 tsp garlic powder, 1 tsp smoked paprika, 1 tsp dried thyme, ½ tsp dried rosemary crushed, and ½ tsp onion powder. Rub the mixture all over the 1 ½ lb pork tenderloin silver skin trimmed, pressing it into the surface on all sides.

Preheat your oven to 425°F. Place an oven-safe skillet (cast iron or stainless steel works best) over medium-high heat and add the 2 tbsp olive oil. Heat until the oil is shimmering and just beginning to smoke.

Add the 1 ½ lb pork tenderloin silver skin trimmed to the hot skillet. Sear without moving it for 2–3 minutes until a deep golden-brown crust forms. Rotate to the next side and repeat, searing all 4 sides (about 8–10 minutes total). Add the 1 tbsp unsalted butter in the last minute and tilt the pan to baste the 1 ½ lb pork tenderloin silver skin trimmed.

Transfer the skillet directly to the preheated oven. Roast for 12–15 minutes, or until an instant-read meat thermometer inserted into the thickest part reads 145°F. Do not overcook — 1 ½ lb pork tenderloin silver skin trimmed is very lean and dries out quickly.

Transfer the 1 ½ lb pork tenderloin silver skin trimmed to a cutting board and tent loosely with aluminum foil. Let it rest for 5–10 minutes — this is non-negotiable for juicy results. The internal temperature will rise a few degrees as it rests.

While the 1 ½ lb pork tenderloin silver skin trimmed rests, return the skillet to medium heat (use insulated gloves — the handle is hot!). Add the 3 cloves garlic minced and sauté for 30 seconds until fragrant.

Pour in the ½ cup chicken broth and scrape up all the browned bits from the bottom of the pan with a wooden spoon — that's pure flavor. Stir in the 1 tbsp Dijon mustard and let the sauce simmer for 2–3 minutes until slightly reduced.

Remove the skillet from heat and swirl in the cold 1 tbsp unsalted butter pieces one at a time until melted and the sauce is silky. Add fresh dried thyme leaves if using. Taste and season with 1 tsp kosher salt and ½ tsp black pepper freshly ground as needed.

Slice the rested 1 ½ lb pork tenderloin silver skin trimmed into medallions about 1 inch thick. Arrange on a serving platter, drizzle generously with the pan sauce, and serve immediately.