Instructions:
- Pat steaks very dry. Press the cracked peppercorns liberally onto both sides of the steaks, along with a pinch of salt.
- Heat oil in a heavy-bottomed skillet over medium-high heat until shimmering. Sear steaks undisturbed for 3–4 minutes per side until a deep crust forms.
- Reduce heat to medium, add butter, and baste the steaks continually until they reach your desired internal temperature (e.g., 130°F/54°C for medium-rare). Remove steaks from the pan and let them rest on a warm plate, loosely tented with foil.
- Return the pan to medium heat. Add the minced shallots to the rendered fat and sauté gently until softened (about 2 minutes).
- Remove the pan from the heat temporarily. Pour in the Cognac/Brandy. Return to the heat and allow the alcohol to reduce completely, scraping up any browned bits (fond) from the bottom. If flambéing, do so carefully. If not, boil vigorously for 1 minute.
- Add the beef broth, scraping the bottom well. Let the liquid reduce by half until slightly syrupy.
- Whisk in the heavy cream and Dijon mustard. Bring to a gentle simmer and allow the sauce to simmer for 3–5 minutes until it lightly coats the back of a spoon. Stir in Worcestershire sauce if using.
- Taste and adjust seasoning. For a silkier texture, strain the Au Poivre Sauce through a fine-mesh sieve, discarding solids.
- Spoon the warm Au Poivre sauce generously over the rested steaks. Garnish with fresh parsley and serve immediately.