Step 1

Remove any twine from 4 beef tenderloin steaks. Let sit at room temperature for 30 minutes. Meanwhile, finely mince 1 small shallot. Coarsely crush 2 tablespoons whole peppercorns in a mortar and pestle, or place the peppercorns in a kitchen towel and crush them with a meat tenderizer or cast iron pan.

Step 2

Season the steaks all over with 1 teaspoon kosher salt. Use your hands to press the crushed pepper onto the top and bottom of the steaks.

Step 3

Heat a large cast iron or stainless steel skillet over high heat until it starts to smoke. Add 1 tablespoon olive oil and 1 tablespoon of the unsalted butter, then add the steaks and cook until medium-rare and a brown crust forms, 2 to 3 minutes per side (an instant-read thermometer inserted into the steak should register about 130°F). Transfer the steaks to a plate or clean cutting board and cover with aluminum foil.

Step 4

Reduce the heat to medium. Add 1 tablespoon of the unsalted butter and shallot. Sauté until the shallot is translucent, about 1 minute. Remove the pan from the heat. Add 1/4 cup Cognac. Return the pan to medium heat and simmer, scraping up any browned bits stuck to the bottom of the pan, until mostly evaporated, 1 to 2 minutes.

Step 5

Add 1/2 cup beef stock, increase the heat to medium-high, and simmer until reduced slightly, 2 to 3 minutes. Add 1/2 cup heavy cream and the remaining 1 tablespoon unsalted butter. Stir until the sauce thickens enough to coat the back of a spoon, 2 to 3 minutes. Stir in accumulated juices on the steak plate or cutting board. Serve the steaks on a bed of the sauce, with more sauce spooned on top.