Pat the flank steak thoroughly dry with paper towels. Season both sides generously with salt or your choice of spices. Allow the steak to sit at room temperature for 30 minutes to ensure it cooks evenly throughout.

Preheat your air fryer to 400°F and allow it to run empty for about 5 minutes. Starting with a hot air fryer basket helps the meat begin searing immediately upon contact.

Place the seasoned flank steak into the center of the air fryer basket. If the steak is too long for your basket, you may gently curl the edges or cut it into two smaller pieces.

Cook at 400°F for 10 to 12 minutes total. To ensure an even brownness on both sides, carefully flip the steak at the halfway mark (about 5 to 6 minutes into the cooking cycle).

Remove the steak from the air fryer and transfer it to a cutting board. Let the meat rest undisturbed for 5 to 10 minutes. This resting period allows the muscle fibers to relax and retain their juices.

Once rested, use a sharp knife to slice the steak into thin strips against the visible grain of the meat. Serve warm. Leftovers can be stored in an airtight container in the refrigerator for up to 4 days.