Remove the filet mignon from the refrigerator 30 to 45 minutes before cooking
Pat the steak completely dry with paper towels
Season both sides generously with salt and black pepper
Heat a heavy skillet, preferably cast iron, over medium-high heat
Add a small amount of high-smoke-point oil to the pan
Place the steak in the hot skillet
Sear for 2 to 3 minutes without moving it
Flip the steak and sear the other side for 2 to 3 minutes
Sear the edges briefly if needed
Reduce the heat to medium or medium-low
Add butter, garlic, and herbs if desired
Spoon the melted butter over the steak while it cooks
Cook until the internal temperature reaches your preferred doneness
Remove the steak from the pan
Rest the steak on a plate or cutting board for 5 to 10 minutes
Slice and serve