Begin by peeling the outer layer of the large onion. Place it root side down on your cutting board. Using a sharp knife, carefully slice the onion into petals, making cuts from the top down. Be cautious not to cut all the way through; leave about half an inch at the root so that the onion stays intact and blooms beautifully.
Preheat your oven to 400°F (200°C). This ensures that your onion will bake evenly and become crispy.
In one mixing bowl, combine the flour, garlic powder, paprika or chili powder, black pepper, and salt. In another bowl, whisk together the egg and milk until well combined.
Dip the prepared onion into the flour mixture, making sure to coat each petal thoroughly. Shake off any excess flour. Next, dip the onion into the egg mixture, allowing the excess to drip off. Finally, coat the onion with the panko breadcrumbs, pressing gently to ensure the crumbs stick well.
Place the breaded onion onto a baking sheet lined with parchment paper. Bake in the preheated oven for about 25-30 minutes, or until the onion is golden brown and crispy. You may want to turn the baking sheet halfway through to ensure even baking.
Once baked, remove the onion from the oven and let it cool for a few minutes. Serve it warm with your favorite dipping sauces, such as ranch or a spicy aioli, and watch it disappear in no time!
