Prep the onions: Trim about 1/4 inch off the top (stem end). Leave the root end intact—it holds the “bloom” together. Peel off the papery skin.

Make the cuts: Place an onion root-side down. Starting about 1/2 inch from the root, make 8–12 vertical cuts around the onion, like slicing a pie. Gently spread the layers into petals. Repeat with remaining onions.

Soak briefly (optional but helpful): If petals are tight, soak cut onions in cold water for 10 minutes, then drain and pat very dry. This helps them “bloom.”

Set up your dredging station: In bowl 1, whisk flour, salt, smoked paprika, garlic powder, onion powder, black pepper, and cayenne. In bowl 2, whisk eggs and milk. In bowl 3, add panko.

Dredge in flour: Sprinkle and press the seasoned flour into and between the petals so everything is lightly coated. Shake off excess.

Dip in egg wash: Hold the onion by the root and dunk it into the egg mixture, letting it run between the petals. Let excess drip off.

Coat with panko: Spoon and press panko into and around the petals. Be gentle but thorough. The more coverage, the crispier the result.

Preheat the air fryer: 375°F (190°C) for 3–5 minutes. Lightly spray the basket.

Arrange and spray: Place onions cut-side up in a single layer without crowding. Generously mist the tops with oil spray to help browning.

Air fry: Cook at 375°F for 12–16 minutes, until deep golden and crisp. Smaller onions may be done around 12 minutes; larger ones can take closer to 16. If needed, rotate the basket halfway through for even color.

Season and serve: Sprinkle with a pinch of salt while hot. Serve immediately with dipping sauce and lemon wedges.

Make the sauce (optional): Stir mayo, ketchup, horseradish, smoked paprika, lemon juice, and salt until smooth. Adjust to taste.