In a small bowl, mix the coffee, chili powders, cumin, coriander, garlic powder, onion powder, and salt. Rub the mixture generously over the steak, pressing it into the surface.
Heat a large skillet over medium-high heat. Once hot, add the steak and sear until deeply browned, about 5 minutes per side.
Reduce the heat to medium. Add the butter and garlic halves to the pan, letting the butter melt and foam. Place the thyme sprigs on top of the steak. Using a spoon, continuously baste the steak with the melted butter for about 2 minutes, or until it reaches your desired doneness (125°F for medium-rare).
Transfer the steak to a cutting board and let it rest for 5 minutes. Slice against the grain and serve with any remaining pan juices.