Pat the filet mignon dry with paper towels
Season generously with salt and black pepper
Let the steak sit at room temperature for 20 to 30 minutes
Heat a heavy skillet over medium-high heat until very hot
Add a small amount of high-smoke-point oil to the pan
Place the filet mignon in the skillet and do not move it
Sear for 2 to 4 minutes on the first side
Flip the steak and sear for 2 to 4 minutes on the second side
Sear the edges briefly with tongs
Add butter, garlic, and herbs if desired
Spoon the melted butter over the steak while cooking
Check for doneness with a meat thermometer
Remove the steak from the pan when it reaches the desired temperature
Rest the steak for 5 to 10 minutes before slicing
Slice and serve