01 - Pat the steaks thoroughly dry with paper towels. Season both sides generously with salt and freshly ground black pepper.
02 - Heat vegetable oil in a heavy skillet over medium-high heat until shimmering. Sear the steaks for 3-4 minutes per side for medium-rare, adjusting time to desired doneness. Transfer to a plate and tent loosely with foil to rest.
03 - Reduce heat to medium. Add butter and minced shallot to the same skillet. Sauté for 1 minute until softened and fragrant.
04 - Add the drained, lightly crushed green peppercorns to the skillet. Sauté for 30 seconds to release their aroma.
05 - If using Cognac or brandy, carefully add it to the pan and flambé, allowing the alcohol to burn off completely.
06 - Pour in the beef stock and bring to a boil, scraping up any caramelized bits from the bottom of the pan. Let the liquid reduce by half.
07 - Stir in the heavy cream and simmer for 2-3 minutes until the sauce thickens to a luscious consistency. Season with salt to taste.
08 - Return the rested steaks to the pan to warm through briefly, or plate the steaks and spoon the creamy peppercorn sauce generously over the top. Serve immediately.