Preheat your air fryer to 400℉ for about 3-5 minutes, depending on the model.
Combine all the ingredients in a little bowl and stir till combined, except the fish.
Pat the fish dry with a paper towel, then pour the marinade over it. Use your hand to coat the fish perfectly.
Place the seasoned mackerel steaks in the air fryer basket in a single layer. Make sure they are not overlapping to allow even cooking
Air fry the mackerel 400℉ for 20 minutes, flipping halfway through cooking time. The exact cooking time may vary depending on the thickness of the steaks and the air fryer model, so check for doneness. The internal temperature should be around 145°F (63°C). The flesh should be opaque and easily flake with a fork.
Once cooked, remove the mackerel steaks from the air fryer and serve
Notes
To deepen the flavor, let the fish marinate for 2-3 hours. Make sure you cover the bowl with cling wrap or an airtight lid and refrigerate it until you are ready to air fry it.
Make sure you pat dry the fish and remove any excess moisture from the surface with paper towels before you marinate it. This will help make the fish crispy when it is air fried.
Don't overcrowd the Air Fryer basket. Leave a little space between the fish pieces to let the hot air circulate through the basket.
Remember to flip the fish over midway through the cooking time. This will ensure that the fish is crispy on both the sides.
You can also baste the fish with some of the leftover marinade or butter while Air frying it to get it some extra crispiness.