Prepare 4-ounce tuna steaks by sprinkling a small pinch of salt and pepper on one side of each portion. For this recipe, you need steaks that are at least 1-inch thick. Set the tuna steaks aside, and make your air fryer breading on a clean plate. Combine almond flour, parmesan cheese, onion powder, garlic powder, italian seasoning, and lemon pepper seasoning. If your lemon pepper seasoning does not include salt, you may wish to include an extra pinch of salt in the breading.
Turn on your air fryer to preheat to 375 degrees. You do not need to dredge the tuna steaks before breading them. Use a clean hand to press each tuna steak into your plate of breading, making sure all exposed sides are coated. Flip the steaks and roll the edges in the breading as necessary to ensure a full but thin layer of coverage. Arrange all breaded tuna steaks on your air fryer tray.
Cook the tuna steaks for 20 minutes or until the tops of the tuna steaks are golden brown and the tuna is cooked through. This recipe makes a well-done tuna steak. For a more rare steak, turn the air fryer up to as high as 425 degrees and cook until the breading on top of the steaks turn golden. Allow the finished tuna steaks to rest for a few minutes before slicing. Allow them to cool entirely before locking them away in containers in your refrigerator.