Pat the steak extremely dry on all sides using paper towels to remove surface moisture.
Season the steak generously with kosher salt and pepper on both sides immediately before cooking.
Place a cast-iron skillet over high heat until it is smoking slightly and the oil ripples.
Carefully lay the steak into the pan away from you to avoid oil splatters.
Sear for about 1 minute without moving it, then flip every minute to ensure an even brown crust develops.⏱ 1 min
Continue flipping and searing until the internal temperature reaches 125°F for medium-rare, about 6–8 minutes total.⏱ 8 min
Add the butter, smashed garlic, and herbs to the pan in the last minute of cooking.
Tilt the pan slightly and use a large spoon to baste the foaming, herb-infused butter over the steak continuously.
Remove the steak to a cutting board and let it rest for at least 5 to 10 minutes before slicing.⏱ 10 min