Start by trimming any excess fat or silver skin from the beef tenderloin. Season the meat generously all over with salt and freshly cracked black pepper. This step is crucial for locking in flavor while cooking. Preheat your oven to 425°F (220°C).
Grab a small bowl and combine olive oil, minced garlic, chopped rosemary, and thyme. Mix until it forms a fragrant paste. Use your hands to massage this mixture into the tenderloin, ensuring every inch is covered for maximum flavor infusion.
Heat a cast-iron skillet over medium-high heat with a drizzle of olive oil. Once the skillet is hot, sear the tenderloin on all sides until it develops a beautiful, golden-brown crust. This step enriches the flavor and keeps the meat tender.
Place the skillet with the seared tenderloin directly into the preheated oven. Roast for about 20-30 minutes, depending on your preferred level of doneness. Use an oven thermometer to check the meat's internal temperature (135°F/57°C for medium-rare).
After roasting, remove the tenderloin from the skillet and allow it to rest on a cutting board for 10-15 minutes. Resting redistributes the juices, making every bite moist and flavorful. Slice the tenderloin into thick medallions for serving.