Remove the steaks from the fridge at least an hour before cooking. Season the steaks liberally with the salt as soon as it comes out of the fridge.
Heat the grill to a low temp. We’re using Ninja Woodfire Outdoor Grill to cook these steaks at 185 degrees F. We’re also using the Meater Block so we can monitor both sides of each steak. Cook the steaks to 125 degrees F, about 50 minutes.
Beat together the butter, lemon juice, brown mustard, parsley, garlic and salt in a medium mixing bowl with a fork. Set aside.
Remove the steaks from the grill and crank the heat up to high. Sear the steaks on all sides over high direct heat. The rest the steaks with some of the butter directly on top to season.
For serving, you’ll cut the steak away from the bone. Use a sharp knife to remove the steak by cutting along the bone. Slice the steak into 1-inch pieces and then return to their position around the bone.