Preheat and prep. Heat the oven to 400°F (200°C). Line a sheet pan with foil and set a wire rack on top if you have one. Pat the pork tenderloin dry with paper towels.

Trim the tenderloin. Slide a small knife under the silverskin and remove it. This helps the meat stay tender and lets the crust adhere better.

Season simply. Sprinkle the pork with 1/2 teaspoon salt and 1/4 teaspoon pepper. Let it rest while you make the crust.

Mix the crust. In a bowl, combine Parmesan, panko, garlic powder, onion powder, Italian seasoning, smoked paprika, and the remaining salt and pepper. Drizzle in 1 tablespoon olive oil and toss to coat the crumbs so they crisp in the oven.

Make the “glue.” In a small bowl, stir together Dijon and mayonnaise. This thin layer helps the crust stick and adds flavor.

Sear the pork. Heat a large oven-safe skillet over medium-high. Add 1 tablespoon olive oil and the butter. Sear the tenderloin on all sides until lightly browned, about 4–5 minutes total. Turn off the heat.

Dress and crust. Brush the seared pork all over with the Dijon-mayo mixture. Press the Parmesan crumb mixture onto all sides, patting firmly so it adheres. If any falls off, scoop it up and press it back on.

Roast. Transfer the skillet to the oven (or move the pork to the prepared rack). Roast for 12–18 minutes, depending on thickness, until the center reads 140–145°F (60–63°C) on an instant-read thermometer.

Rest and slice. Let the pork rest on a cutting board for 5–8 minutes. This redistributes juices and keeps slices moist. Cut into 1/2-inch medallions.

Finish and serve. Sprinkle with chopped parsley or chives, and add a squeeze of lemon if you like. Serve with roasted potatoes, green beans, or a crisp salad.