Choose the cut: beef tenderloin (mignon)
Pat dry with paper towels
Season generously with salt and black pepper
Optional: add a light coating of oil or clarified butter
Preheat oven to 400°F (205°C)
Preheat a heavy skillet over medium-high heat
Sear mignon in the skillet 1–2 minutes per side until browned
Optional: sear the edges briefly as well
Transfer skillet to the oven
Cook to desired doneness:
Rare: 120–125°F (49–52°C)
Medium-rare: 130–135°F (54–57°C)
Medium: 140–145°F (60–63°C)
Optional: during the last minute, baste with butter and aromatics (garlic, thyme) if desired
Remove from oven when target temperature is reached
Rest 5–10 minutes
Slice and serve