Preparation: Make the blue cheese compound butter a few hours or days before needed and refrigerate.

Compound Butter: Mince the parsley and shallot. Put the butter in a small bowl. Stir or mash with a fork until smooth. Stir in the crumbled blue cheese, shallot, and parsley until combined. Scoop the compound butter onto a piece of waxed paper, centering it lengthwise down the middle of the paper. Roll into a log, twist the ends, and refrigerate. Remove from the refrigerator just before cooking the steaks.

Flat Iron Steaks: Remove the steaks from the refrigerator 20-30 minutes before cooking. Place the pepper corns in an electric coffee grinder and process until they are a very coarsely ground. Alternately, crush the peppercorns with a heavy skillet by applying downward pressure against a cutting board.

Place a cast iron skillet over medium heat to get hot.

Meanwhile, dry the steaks with a paper towel. Rub a little olive oil over all surfaces and season with salt. Pour the coarsely ground peppercorns onto a plate and evenly coat the tops and bottoms of the steaks, pressing the pepper firmly into the meat. Add the bacon grease (or olive oil) to the hot pan and swirl to coat the bottom. Add the steaks and let cook for 5-7 minutes minutes per side, depending on how thick the steaks are and how well you like yours cooked. For medium rare remove the steaks from the heat at 135 degrees F and for medium at 155 degrees F.

Remove the steaks to a plate and tent loosely with foil for 15 minutes. Don't skip this step, it's crucial for a juicy steak. Top with a slice of compound butter.