01 - Remove steaks from refrigerator 30 minutes before cooking to reach room temperature. Pat dry thoroughly with paper towels.
02 - Generously season both sides of each steak with kosher salt and freshly ground black pepper.
03 - Heat olive oil in a large cast iron skillet over high heat until shimmering.
04 - Place steaks in the hot pan and sear for 3 to 4 minutes per side for medium-rare doneness. Remove steaks, tent loosely with foil, and let rest while preparing sauce.
05 - Reduce heat to medium. Add butter to the same skillet and melt. Add minced garlic and sauté for 1 minute until fragrant.
06 - Pour in beef broth and scrape up browned bits from the bottom of the pan.
07 - Stir in heavy cream and bring to a gentle simmer. Add Dijon mustard and Parmesan cheese, stirring continuously until sauce is smooth and slightly thickened, about 2 to 3 minutes.
08 - Stir in chopped fresh parsley. Season with salt and pepper to taste.
09 - Slice rested steaks against the grain. Plate steaks and spoon creamy garlic sauce generously over the top. Garnish with additional fresh parsley if desired.