Preheat your oven to 425°F. Place the rack in the middle position.

Place a large cast-iron skillet over high heat until very hot. (Make sure to use oven mitts.)

Rub the steak with 1/2 tablespoon of oil, and then season with salt and pepper.

Add the remaining oil to the pan and swirl to coat. Place the filet mignons in the pan.

Sear the first side for 2 minutes. Then flip and sear the other side for 2 more minutes.

Add the garlic and butter. Then transfer the steak to the oven.

Bake for about 4-5 minutes for medium-rare doneness (125-130°F ), measuring the internal temperature using an instant-read thermometer.

Allow the steak rest for 5 minutes on a plate before cutting. Serve and enjoy!