Trim off any silver skin — it won't break down and will make the meat tough. Pat the tenderloin completely dry with paper towels; surface moisture kills your sear. Season all over with kosher salt and black pepper, plus any dry rub or spice blend you like (garlic powder, herbes de Provence, etc.). To marinate, seal in a bag and refrigerate at least 1 hour or up to overnight. If cooking right away, let it rest at room temperature for a few minutes while the skillet heats. Keep an instant-read thermometer handy to confirm doneness.

Heat 2 tbsp neutral oil (grapeseed or olive) in a large heavy skillet over medium-high until shimmering and nearly smoking. Lay the tenderloin in and cook undisturbed ~5 minutes on the first side until deep golden brown and it releases easily. Sear remaining sides, turning occasionally, for a total searing time of 6–8 minutes across all sides. Transfer the skillet (if oven-safe) or move pork to a baking dish to a preheated 400–425°F oven. Flip once halfway through. Roast 14–19 minutes, checking internal temp at the 14-minute mark. Pull when a thermometer in the thickest part reads 140–145°F. Center will be slightly pink — that's correct. Do not rely on color alone.

Once pork hits 140–145°F, move it to a cutting board and tent loosely with foil. Rest at least 5 minutes, ideally 10 — skipping this step lets the juices run out and leaves the meat dry. Temperature will rise a few degrees during rest; that's normal. Slice about ½ inch thick across the grain and spoon any pan juices over the top. Don't go past 150°F — this cut dries out fast. Trust your thermometer, not how it looks.