Bring the meat to room temperature, at least 1 hour before cooking. Pat dry.
Set the Traeger grill (or oven) to 220°F.
Generously season meat all over with salt and pepper, then the Seattle Espresso rub. Allow the meat to sit with the seasonings for at least 1/2 hour before cooking. Place the meat on the Traeger grill (or place in the oven on a rack sitting in a sheet pan), and close the grill. Cook until the internal temperature reaches 110°F. Our 4 pound tomahawk took 1 hour in the Traeger. Allow the meat to rest for at least 15 minutes at room temperature before you take the next step.
Make sure the grill grates are well oiled. Pre-heat your grill, or prepare the charcoal grill for high heat. Place the meat on the grill, and sear for 2-3 minutes per side. Test the internal temperature: 115°F (46°C) for medium-rare, 125°F (52°C) for medium, or 135°F for well-done.
We like to add the Florentine touch to our steaks, which is a post-cook marinade. Add the olive oil to a deep platter, then add the rosemary and garlic. Transfer the meat to the platter and tent with foil. Wait for 5 minutes, flip the steak, then wait 5 more minutes. Then it's time to cut and serve.