Take the tomahawk steak out of the refrigerator and let it come to room temperature for about 30-60 minutes before cooking. Preheat your oven to 375°F (190°C).

In a small bowl, combine the mashed black garlic, crushed pink peppercorns, salt, and freshly ground black pepper. Rub the mixture all over the tomahawk steak, ensuring it is evenly coated.

Heat the olive oil in a large oven-safe skillet over medium-high heat. Once the oil is hot, add the tomahawk steak and sear it for about 4-5 minutes on each side, until a nice crust forms.

Transfer the skillet to the preheated oven and roast the steak for 30-45 minutes, or until it reaches your desired level of doneness (130°F for medium-rare, 140°F for medium). Use a meat thermometer to check the internal temperature.

While the steak is roasting, combine the beef broth and truffle oil in a saucepan over medium heat. Bring it to a simmer and let it reduce by half, which should take about 15-20 minutes.

In a separate small pan, melt the butter and whisk in the flour (if using) to create a roux. Cook for about 2 minutes. Gradually whisk the roux into the reduced beef broth until smooth. Add the chopped thyme and continue to simmer until the gravy thickens.

Once the steak is done, remove it from the oven and let it rest for at least 10 minutes before slicing. Serve the sliced tomahawk steak drizzled with the truffle thyme gravy.