Instructions

1. Pat steaks dry and season both sides with kosher salt.
2. Coarsely crush peppercorns in a sealed plastic bag with a meat pounder or the bottom of a heavy skillet, then press most of the pepper evenly onto both sides of steaks (reserve 1 teaspoon).
3. Heat a large cast-iron skillet over moderately high heat until hot, about 3 minutes. Melt 1 tablespoon of the butter and sauté the steaks in 2 batches, turning over once, about 6 minutes per batch for medium-rare.
4. Transfer the steaks to a heatproof platter and keep warm in oven while making sauce.
5. Pour off the fat from the skillet, then add the shallots and the remaining 2 tablespoons of butter to the skillet. Cook over medium-low heat, scraping up any brown bits and stirring until the shallots are well-browned, 3-5 minutes.
6. Carefully add the Cognac, leaning back to avoid any accidents (it may ignite). Boil, stirring, until the alcohol has burned off and the liquid is reduced to a glaze, 2-3 minutes.
7. Increase the heat to medium and add the beef stock and creme fraiche. Cook, stirring occasionally, until the sauce is reduced by half, 5-7 minutes. Serve the sauce over the steaks.