Instructions
Slice off the onion stem and set the onion on its flat side.
Cut an inch from the root down into 12 sections, being careful not to cut all the way through.
Flip over and gently pull out sections of the onion to separate petals.
In a shallow bowl, whisk together eggs and 1 tablespoon water.
In another shallow bowl, whisk together breadcrumbs and spices.
Dip the onion into the egg wash, then dredge it in the breadcrumb mixture, using a spoon to coat fully.
Drizzle the onion with oil.
Place in the basket of your air fryer and cook at 375° until the onion is tender all the way through, 25 minutes.
Drizzle with more oil as desired.
Make the sauce by whisking together mayonnaise, ketchup, horseradish, paprika, garlic powder, and dried oregano in a medium bowl.
Season with salt.
Serve the onion with the sauce for dipping.
Pro Tips
Be careful not to cut all the way through the root when slicing the onion to keep the petals attached.
Use a spoon to ensure the breadcrumb mixture coats the onion petals fully.
Drizzle with extra oil during cooking if the breadcrumbs look dry to ensure a crispy texture.