How to Make It
On a work surface, using the flat side of a chef's knife, mash the garlic to a paste with the salt. Scrape the garlic into a small bowl. Stir in the paprika, cayenne and oregano. Gradually stir in the olive oil. Spread the mixture on a large platter, add the steaks and turn to coat, rubbing in the marinade. Let stand at room temperature for 1 to 4 hours or refrigerate overnight.
Meanwhile, in a medium bowl, mash the butter with the shallot and scallion. Stir in the Valdeón. Scrape the blue cheese butter onto a sheet of plastic wrap and pat it into a 4-inch log. Wrap and refrigerate until firm, at least 30 minutes.
Light a grill or preheat a grill pan. Scrape some of the marinade off the steaks and grill over a medium-hot fire, turning once, about 8 minutes for medium-rare meat. Slice the butter 1 inch thick, set a pat on each steak and serve.