
Steak au poivre may sound fancy, but with a few simple ingredients, you can make this French bistro favorite in under 30 minutes.
Pat the steaks dry and, if they are thick, gently press them down so that they are about 1½ inches thick. Season the steaks all over with the salt.
Seal the peppercorns inside a small plastic bag and place on a cutting board. Using a meat mallet or the bottom of a frying pan, pound the peppercorns until they are coarsely crushed. Press the crushed pepper evenly onto both sides of the steaks.
In a large stainless steel or cast iron skillet, heat the oil over medium-high heat. When the oil is hot and shimmering, add the steaks and cook about 4 minutes on each side, turning only once, for medium-rare (or about 5 minutes per side for medium). Transfer the steaks to a plate and tent with foil.
Pour off the excess fat from the pan but do not wipe clean. Lower the heat to medium-low and add the butter and shallots. Cook, stirring constantly with a wooden spoon and scraping up the brown bits, until the shallots are golden brown and softened, 2 to 3 minutes. Carefully add the Cognac (it may ignite) and boil, again stirring to scrape up the brown bits, until the liquid is reduced to a glaze and mostly absorbed by the shallots, a few minutes. Add the cream and mustard and gently boil until thickened, about 3 minutes. Stir in any meat juices that accumulated on the plate. Transfer the steaks to plates and spoon the sauce over top.