Preheat the air fryer.
Add the onions to a medium sized bowl.
Mix together the milk with the vinegar and leave for 5 minutes.
Pour the milk over the onions and leave to soak for about 10 minutes.
Meanwhile, in another bowl, add the brown rice flour, amaranth flour, tapioca starch, oat bran, paprika the black pepper and pink salt.
Whisk and combine the flour, seasoning and starch.
Use a slotted spoon to remove the onions from the milk and toss them in the flour.
Use a large spoon to completely coat the onions with the flour blend (you may find it easier to put the flour and onions in a zip lock bag and shake it instead). .
Lightly spray or coat the air fryer basket with oil.
Use a slotted spoon to carefully add the onions to the basket, you may need to do this in batches.
Air fry the onions at 375F/180C for 8-12 minutes, after 3 minutes stop and shake the basket then lightly spray the tops of the onion with oil.
Resume air frying stopping and shaking the basket every few minutes.
Once cooked allow to cool before using accordingly.
