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, pressing the seasoning into the meat.
03 - Heat olive oil in a large cast iron skillet over high heat until shimmering and just beginning to smoke.
04 - Add steaks to the hot pan and sear for 3-4 minutes per side for medium-rare doneness, or adjust time to your preference.
05 - Transfer steaks to a plate, cover loosely with aluminum foil, and let rest while preparing the sauce.
06 - Reduce heat to medium. Add butter to the same skillet and melt. Sauté minced garlic for 1 minute until fragrant, being careful not to burn.
07 - Pour in beef broth and scrape up all browned bits from the bottom of the pan with a wooden spoon.
08 - Stir in heavy cream and bring to a gentle simmer. Let cook for 2-3 minutes until slightly thickened.
09 - Add Dijon mustard and Parmesan cheese, stirring constantly until cheese is melted and sauce is smooth. Stir in parsley and season with salt and pepper to taste.
10 - Slice the rested steaks against the grain and arrange on plates. Spoon the creamy garlic sauce generously over the top and garnish with additional fresh parsley if desired.