Preheat oven to 425°F
Pat filet mignon dry with paper towels
Season both sides with salt and black pepper
Heat an oven-safe skillet over medium-high heat
Add a small amount of oil to the skillet
Sear the filet mignon for 2 to 3 minutes per side
Add butter, garlic, and herbs if desired
Transfer the skillet to the oven
Bake for 5 to 10 minutes, depending on thickness and desired doneness
Check internal temperature with a meat thermometer
Remove at 125°F for rare
Remove at 130°F for medium-rare
Remove at 140°F for medium
Remove from the oven and let rest for 5 to 10 minutes
Slice and serve