Peel the onion and cut it into approximately ½-inch-thick slices. Carefully separate the slices into individual rings.

Place the flour in a shallow bowl.

In a second shallow bowl, whisk the eggs and milk together until evenly combined.

Add the panko breadcrumbs to a third shallow bowl.

Coat each onion ring first in flour, shaking off any excess.

Dip the floured ring into the egg and milk mixture, allowing the excess to drip back into the bowl.

Press the onion ring gently into the panko breadcrumbs until completely coated. Transfer to a plate and repeat with the remaining rings.

Pour approximately 2 inches of vegetable oil into a deep, heavy saucepan or skillet. Heat to 375°F (190°C).

Working in small batches, carefully lower the Deep Fried Onion Rings into the hot oil without overcrowding the pan.

Fry for approximately 2–3 minutes per side, or until crisp and deeply golden.

Carefully remove the onion rings and transfer them to a paper towel-lined plate or wire rack to drain.

Season lightly with salt while still warm. Allow them to cool slightly before serving with your favorite dipping sauce.