I love a good Grilled Porterhouse Steak but it's the Paprika-Parmesan Butter that makes this recipe!
Mix all Paprika-Parmesan Butter ingredients in a small bowl until blended.(Can be made 2 days ahead.)
Use at room temperature.
Place steak in a glass baking dish.
Whisk oil and next 5 ingredients in a small bowl to blend. Pour half of the marinade over steak. Turn steak over; pour remaining marinade over steak. Cover and chill at least 2 hours and up to 1 day, turning occasionally.
Remove steak from marinade; shake off excess.
Place steak on grill; cover grill.
Grill steak to desired doneness, (until an instant-read thermometer inserted into the center of steak registers 115 F to 120 F for rare, about 15 minutes per side, or 125 F to 130 F for medium-rare, about 18 minutes per side), occasionally moving steak to a cooler part of the rack if cooking too quickly.
Transfer steak to platter; cover to keep warm. Let stand for 5 minutes.
Using a sharp knife, cut meat away from the bone. Cut each meat section into 1/3-inch-thick slices.
Spread Paprika-Parmesan Butter over top of slices and serve.