01 - Let the beef tenderloin steaks come to room temperature for 20–30 minutes. Pat dry thoroughly with paper towels to ensure proper searing.
02 - Season steaks generously with kosher salt and black pepper on both sides, pressing the seasoning into the meat.
03 - Heat the olive oil and 1 tbsp butter in a large skillet over medium-high heat until the butter foams and the pan is hot.
04 - Add the steaks to the hot pan. Sear for 3–4 minutes per side for medium-rare, adjusting time to achieve desired doneness.
05 - Transfer steaks to a plate, tent loosely with foil, and let rest while preparing the sauce.
06 - Reduce heat to medium. Add green peppercorns to the same skillet and toast for 30 seconds until fragrant.
07 - Pour in white wine, scraping up any browned bits from the bottom. Let reduce by half, about 2–3 minutes.
08 - Add beef stock and simmer until slightly reduced, another 2 minutes.
09 - Lower heat and stir in heavy cream and Dijon mustard. Simmer gently until thickened, 3–4 minutes.
10 - Stir in 1 tbsp butter. Taste and adjust seasoning with salt if needed.
11 - Return the steaks to the pan to coat in the sauce, or spoon sauce generously over each steak to serve.