Place a large cast-iron or heavy-bottomed pan over high heat, pouring in a thin layer of grapeseed oil.
Season the rib eye generously with salt and pepper.
When the pan is very hot and the oil is shimmering, sear the steak until a golden-brown crust has formed, 3 to 4 minutes.
Reduce the heat to medium-high and turn over the steak. Arrange the shallots, garlic (cut-sides down), thyme, and sage around the steak.
Continue to cook for 3 to 4 minutes.
Using a digital meat thermometer, when the internal temperature of the steak hits 118°F, add the butter, allowing it to foam, then baste the steak fifteen to twenty times. Transfer the meat to a cutting board and allow it to rest for 10 to 15 minutes.
The final internal temperature will climb to 123°F to 126°F.