Cut off 1/2 inch from the top of the onion, and peel the outer skin.
Place the onion cut-side down onto a cutting board and starting about 1/2 inch from the root, make a downward cut all the way through to the board through the middle of the onion. All your cuts should meet in the middle. But do not cut through the root or too close to the root.
Make 4 evenly spaced cuts, after that 1 additional cut in between each section, this way you will have 8 evenly spaced cuts.
Turn the onion over and let it sit for 10 minutes to allow the petals to relax. Use your fingers to gently separate the petals.
Bread the onion:
In a large bowl whisk the flour and spices.
In a small deep bowl, whisk the egg, butter, and milk.
Place the onion in a large shallow dish bowl, cut-side up. Make sure the petals are separated.
Sprinkle the flour mixture over the onion making sure to get it in between the layers. Use a fork to get it in between the onion petals.
Repeat with the other onion.
Sprinkle the remaining flour mixture on top of the onions. Set them aside for a few minutes.
Shake the excess flour into a bowl.
Add the onions to a large bowl and pour the egg mixture on top to coat evenly. Try getting the egg mixture in between the petals. Let the onion sit in this mixture for a few minutes. Tilt the onions and let the excess egg mixture drip off.
Sprinkle the reserved flour mixture and panko bread crumbs on top of the onions.
Place the onions into the refrigerator to set (for about 10 minutes) while you preheat the air fryer.
Preheat the air fryer to 300 degrees F.
Spray onions generously with cooking oil. Place on a piece of foil and air fry for 20 minutes or until crispy and golden brown.
Open and spray at once or twice with more cooking oil during the cooking process.
Remove gently and serve with your favorite dipping sauce.
Do not take off the root, or the entire bulb will fall apart.
You’ll need to be very generous when spraying with oil, so you can get that crunchy, deep-fried effect.
Push the sections open to make them open up but be careful so you don’t tear off the sections.
If there are still any dry spots of flour, dab or brush it with more buttermilk-egg wash.