Filet mignon is a steak cut taken from the tenderloin. It's one of -- if not the -- most tender types of steak available, though it's a little less flavorful than rib-eyes, sirloin or top loin cuts. Because of its tenderness and ideal fat marbling, a filet mignon does well with dry-heat cooking methods. It's easy to just bake filet mignon, but it's a more standard approach to pan-sear it first. This gives the outside a crispness that contrasts nicely with the soft, juicy interior, and then to finish it in the oven.
Take the filet mignon out of the refrigerator 45 minutes before cooking it. Dry its surface with paper towels and salt all sides liberally with kosher or sea salt. Let it sit out on the counter. By salting this far in advance, there's enough time for the salt to draw moisture out of the meat, and for the moisture to then be reabsorbed, flavoring the steak and helping it stay juicy during cooking.
Preheat the oven to 375 degrees Fahrenheit when you're about 20 minutes away from baking the filet mignon.
Put a heavy, oven-safe skillet over medium-high heat on the stove for 2 to 3 minutes. Roll cooking oil around in the hot pan to coat the bottom.
Pat some freshly cracked pepper onto the filet mignon to taste, and then put the filet mignon in the skillet. Leave it in place. Sear it for about two minutes, then shake the pan gently by the handle. When the steak easily slides, turn it over with tongs and repeat this process for the second side.
Transfer the skillet and filet mignon directly to the middle of the oven. Bake it to 120 F for rare, 130 F for medium-rare, 140 F for medium, 150 F for medium-well or 160 F for well-done; use a cooking thermometer to read the steak's internal temperature at center. As a rough guide, a 1 1/2-inch thick filet mignon needs to bake for about 4 to 5 minutes for rare, 6 to 7 minutes for medium-rare, 9 to 10 minutes for medium, 12 to 13 minutes for medium-well or 15 to 16 minutes for well-done.
Take the filet mignon out of the pan promptly to prevent overcooking. Let it rest for 5 to 10 minutes before serving. During this time, its temperature rises about 5 F and the juices released from muscle fibers during cooking settle back into the muscle fibers, which prevents the juices from running when you cut the meat.