Preheat the air fryer to 390ºF for 5 minutes while you prepare the tuna.
Pat dry the tuna steaks. Rub with oil and season with salt and pepper on both sides.
If your tuna steaks come frozen, thaw them overnight in the fridge OR inside the vacuum-sealed package immersed in a bowl of COLD water.
Air fry the tuna for 2 minutes, flip, then cook for 1-2 minutes more (check the color after 1 minute, the edges will be grey and not pink). This will give you rare tuna steaks, so cook them longer if you prefer medium-rare.
Video
Notes
Always preheat the air fryer. It helps develop a seared crust before the inside overcooks.
You can scale up this recipe as desired but work in batches to keep the tuna steaks in a single layer in the air fryer. For most air fryers, you’ll only be able to fit 2 tuna steaks at a time.
Pat the tuna dry before cooking so it sears instead of steaming.
For best texture, don’t cook past medium unless you’re planning to flake it into something like tuna patties.
Leftovers? Chill and slice for salads or poke bowls the next day.