Preheat your oven to 425 degrees F and line a rimmed baking sheet with foil. Lightly grease the foil with cooking spray or a thin smear of oil.

Remove the silverskin from the tenderloin if the butcher has not already done it. Look for the thin, pearlescent membrane running along one side. Slide the tip of a paring knife under it, angle the blade slightly upward, and pull the membrane back while you run the knife along underneath it. It comes off in one or two strips. This step matters because silverskin does not soften in the oven and can cause the meat to curl and cook unevenly.

Pat the tenderloin dry with paper towels and season all over with salt and pepper. In a small bowl, stir together the Dijon mustard, garlic, rosemary, and thyme. Brush or spread this mixture over the entire surface of the tenderloin, getting it on all sides.

Spread the breadcrumbs in a shallow dish and roll the mustard-coated tenderloin in them, pressing gently so the crumbs stick and form an even layer. Place the coated tenderloin on the prepared baking sheet and drizzle the top with 1 tablespoon of olive oil.

Roast for 20 to 25 minutes, until the crust is golden and an instant-read thermometer inserted into the thickest part of the meat reads 145 degrees F. Start checking at the 20-minute mark because tenderloins vary in thickness and this cut cooks faster than most people expect.

Transfer the tenderloin to a cutting board and let it rest for 5 full minutes before slicing. Resting allows the juices to settle back into the meat. Slice into medallions about 3/4 inch thick and serve immediately with roasted potatoes or sauteed green beans.