01 - Remove steaks from the refrigerator 30 minutes before cooking to bring them to room temperature. Pat dry with paper towels and season generously with salt and pepper on both sides.
02 - Heat olive oil and 1 tablespoon butter in a heavy skillet over medium-high heat. When hot, add the steaks. Sear for 3-4 minutes per side for medium-rare doneness.
03 - Transfer steaks to a plate and tent loosely with foil to rest while preparing the sauce.
04 - Pour off excess fat from the pan, leaving about 1 tablespoon. Add the crushed peppercorns and toast briefly for about 30 seconds.
05 - Carefully add brandy or cognac to deglaze the pan, scraping up brown bits with a wooden spoon. Let alcohol reduce by half for about 1 minute.
06 - Add beef stock and simmer until reduced by half, about 3 minutes.
07 - Lower the heat and stir in heavy cream and Dijon mustard. Simmer until the sauce thickens slightly, 2-3 minutes. Whisk in the remaining tablespoon of butter.
08 - Return steaks to the pan to warm through, spooning sauce over them for 1 minute. Serve steaks topped with peppercorn sauce.