Coat all sides of the trimmed beef tenderloin with a generous amount of salt and cracked mixed peppercorns. Place a large skillet or roasting pan over medium-high flame, drizzle with oil, and just when it comes to the smoking point, lay the peppered tenderloin in the hot pan. Sear on all sides until a crust forms and the meat is browned, about 7 minutes total. Place in oven and roast for 20-25 minutes for medium rare.

Transfer the tenderloin to a cutting board and let rest for 10 minutes before carving. Pour off the excess fat from the pan and put it back on the stove over medium-high heat. Add the shallots to the pan drippings, sauté, stirring with a spoon to scrape up the flavors in the bottom. Take pan off heat and pour in the cognac. Keep your face away from the smoking pan and put the pan back on the heat and tilt it slightly over the burner to ignite the alcohol. The cognac will flame for a few seconds. The flame will go out as the alcohol burns off. Stir in the demi-glace and cream and simmer for about 1 minute to thicken the sauce so that it coats a spoon. Taste and season with salt, if necessary.

Cut the tenderloin into ½-inch-thick slices. Drizzle the sauce over the beef and garnish with chopped parsley. Serve the steak au poivre with matchstick potatoes and grilled asparagus.