Prepare the tenderloin: Trim any excess fat or silver skin from the pork.
Season the pork: In a small bowl, mix garlic powder, smoked paprika, salt, black pepper, thyme, and onion powder. Rub the pork tenderloin with olive oil, then coat it evenly with the seasoning mix.
Sear (optional but recommended): Heat a skillet over medium-high heat and sear the pork on all sides for about 2 minutes per side until golden brown.
Bake: Place the pork on a baking sheet lined with parchment paper or in a baking dish. Brush with Dijon mustard and drizzle with honey if using.
Cook: Bake for 18-22 minutes or until the internal temperature reaches 145°F (63°C) for a slightly pink center.
Rest: Remove from the oven, cover loosely with foil, and let it rest for 5-10 minutes before slicing.
Serve: Slice into medallions and enjoy with roasted vegetables, mashed potatoes, or a fresh salad.