Preheat your air fryer to 370 and prep basket for nonstick
In a mixing bowl, mix together the flour, baking powder and seasonings. Mix in the egg and then the milk (or beer). Transfer to a shallow bowl.
In a shallow bowl , place your bread crumbs
Using a fork, take the first slice of onion and fully cover it with the contents of the first bowl- using a dredging technique. Then dip this piece into the bread crumbs. Then place it into the basket. Repeat this with the other slices- trying to not over-lap too much.