Place the flank steak In a gallon-sized sealable bag and set it aside.
In a medium bowl, combine the rest of the ingredients listed and whisk until combined.
Pour the marinade into the bag with the flank steak. Seal tightly removing any excess air. Store in the refrigerator and marinate for at least 20 minutes or as long as overnight. The longer you can marinate the meat, the more flavorful and tender it will be. Turn the bag occasionally making sure it is marinating evenly on all sides.
When you are ready to air fry the meat, drain the steak from the marinade and discard the marinade.
Preheat the air fryer to 400° Farenheit. Add the steak to the basket and cook for about 5-7 minutes on each side only flipping once. Cook time depends on the thickness of your steak. Cook until the internal temperature reads 140-145° Fahrenheit or 130° Farhenheit for medium-rare. Let rest 5 minutes before slicing.
Thinly slice steak against the grain. Enjoy the meat as is, or serve in tacos, burritos, nachos, or salads.