Take the tomahawk steak out of the refrigerator and let it come to room temperature, about 1 hour before cooking.

In a small bowl, combine the mashed black garlic, chopped marjoram, olive oil, salt, and black pepper to create a paste.

Rub the black garlic and marjoram paste all over the tomahawk steak, ensuring an even coating. Let it marinate for at least 30 minutes to enhance the flavors.

In a separate bowl, mix the softened butter with the cracked long pepper and ground porcini mushrooms until well combined. Set aside.

Preheat your grill to high heat, or if using an oven, preheat it to 450°F (232°C).

Place the tomahawk steak on the grill or in the oven. If grilling, cook for about 4-5 minutes on each side for medium-rare, or until the internal temperature reaches 130°F (54°C). For oven cooking, sear the steak in a hot skillet for 2-3 minutes on each side, then transfer to the oven for about 15-20 minutes.

Once cooked to your desired doneness, remove the steak from heat and let it rest for 10-15 minutes. This allows the juices to redistribute.

Slice the steak against the grain and serve with a generous dollop of the cracked long pepper and porcini-dust butter on top.