To prepare the onion, cut off the stem but leave the root-end in tact. Peel the outer layer of the onion and discard. Placing the onion flat onto a clean work surface, make 12 even cuts starting from ¼-inch below the root all the way downward to your cutting board. Turn the onion over so it’s sitting on its root and gently fan open the layers to resemble a flower.
Place the onion into the boiling water. Cook for 30 seconds. Remove into a bowl of ice water to cool completely.
Preheat the Smart Fryer to 360 degrees F.
In a large mixing bowl, whisk together the flour, salt, pepper, paprika, onion powder and celery seed. Set aside.
In a medium mixing bowl, whisk the egg whites until frothy.
Remove the onion from the ice bath. Pat dry with paper towels.
Submerge the onion in the egg whites, making sure it’s completely coated. Allow any excess to drain off. Then put the onion in the seasoned flour mixture. Dust the onion, getting in between each layer, with the flour. Shake off any excess flour. Spray the onion all over with the vegetable oil cooking spray. Place into the fryer basket and cook for 10 minutes. Increase the heat to 400 degrees and cook for 3 more minutes until golden brown and crispy.