• Season the steaks. Pat the filets completely dry. Season generously on all sides with coarse salt and cracked black pepper. Let sit at room temperature for 20–30 minutes before cooking.
• Make the peppercorn sauce. Melt the butter in a medium saucepan over medium heat. Add the shallots and sauté for 1–2 minutes, stirring often, until softened but not browned. Stir in the crushed peppercorns and toast for 30–60 seconds, until fragrant. Carefully add the cognac or brandy. (Be extremely careful and keep your face back away from the pan after adding. It will briefly flame up at some point while it is simmering.) Simmer until reduced by about half, scraping up any browned bits from the pan. Add the beef stock and simmer for 3–4 minutes, until slightly reduced. Stir in the cream and Dijon mustard. Reduce heat to low and simmer gently until the sauce thickens enough to coat the back of a spoon. Taste and season with fine sea salt as needed. Keep warm over very low heat.

Sear the filets. While the sauce simmers, heat a heavy skillet (cast iron is ideal) over medium-high heat until very hot. Add the oil. Place the steaks in the pan and sear undisturbed for 2½–3 minutes per side, until a deep golden-brown crust forms. Reduce heat to medium. Add the butter, garlic, and herbs. Tilt the pan slightly and spoon the melted butter over the steaks for 30–60 seconds. Use an instant-read thermometer to check for doneness:

• Rare: 120–125°F
• Medium-rare (ideal for filet): 130–135°F
• Medium: 140–145°F
• Medium-well: 150–155°F
• Rest the steaks. Transfer steaks to a plate and tent loosely with foil. Let rest for 5–10 minutes.
• Serve. Spoon the warm peppercorn sauce generously over the rested filets. Serve immediately and enjoy!