Prep the onions: Peel the onions and slice them into 1/2-inch thick rounds. Gently separate into rings. Save the small center pieces for another use or batter them, too.

Set up a breading station: In one shallow bowl, whisk together the flour, cornstarch, salt, pepper, garlic powder, and paprika. In a second bowl, whisk the eggs with the milk. In a third bowl, combine panko, fine breadcrumbs, and Parmesan (if using).

Dry coat first: Working in batches, toss onion rings in the seasoned flour mix. Shake off excess. This layer helps the egg cling.

Dip in egg: Coat each ring in the egg mixture, letting the excess drip off so you don’t end up with clumps.

Final crumb coat: Press each ring into the breadcrumb mixture, turning to coat. Press gently so the crumbs adhere well. Set coated rings on a tray.

Let them rest: Give the coated rings 5–10 minutes to sit. This helps the crust set and reduces shedding in the air fryer.

Preheat and oil: Preheat the air fryer to 375°F (190°C) for about 3 minutes. Lightly spray the basket with oil to prevent sticking.

Load the basket: Arrange onion rings in a single layer with a little space between each. Avoid stacking. Lightly mist the tops with oil spray for even browning.

Air fry: Cook for 6–8 minutes, flipping halfway and misting again after flipping. They’re done when golden brown and crisp. Thicker rings may need up to 10 minutes.

Season and serve: Sprinkle with a pinch of salt the moment they come out. Serve hot with your favorite sauce.

Batch cooking: Repeat with remaining rings. Keep finished rings on a wire rack in a low oven (200°F/95°C) if you’re cooking multiple batches.