Fill a large mixing bowl (4 quarts) ⅔ way full with water and 2 cups of ice.

Remove the outer husk and top layer of skin of the onion. Carefully slice the top of the onion Consider it the North Pole of the onion. Keep the South Pole intact for now. Slice the onion into ½-inch rings. Once you get to the last ring, lay the onion flat and carefully slice the bottom of the onion off.

Carefully separate the onion rings. Place the rings in the ice water for about 5 minutes. This will help dilute the sulfur in the cut rings. If you are using a sweet onion, you can skip this step. Remove the onion rings and drain them on paper towels.

Line a baking sheet with paper towels. Place a cooling rack over the paper towel layer. Set it aside.

Line a second baking sheet with wax paper. You can also use a disposable baking pan or large serving plate.

Add the ¼ cup of cornstarch to a shallow bowl. Dip the drained onion rings in the cornstarch, shaking off any excess, and place on the wax paper.

Add the flour, salt pepper, garlic powder, paprika, and cayenne pepper to a medium size shallow bowl (2-3 quarts). Whisk to combine.

Add the egg to the milk, and use a fork to combine completely. I mixed my egg and milk together in the measuring cup, but you can also mix in a small bowl.

Add the egg and milk mixture to the dry ingredients, whisk to completely incorporate, and remove any flour lumps.

Add the vegetable oil to a 10-inch skillet that’s at least 2½ to 3 inches deep, over high heat, to 370°F-375°F. Use a candy/deep fry thermometer to accurately measure the temperature. While the oil is heating, batter/bread the onion rings.

Add 2 cups of the panko bread crumbs to a shallow bowl. You will need to add the remaining 2 cups of panko crumbs as you bread the remaining onion rings.

Dip the onion rings into the batter, shaking off any excess, then immediately bread the inside and outside of the battered onion rings in the panko bread crumbs. Shake off the excess and place the onion rings back onto the wax paper-covered baking sheet.

Once the oil has reached 370°F-375°F, carefully add 3 to 4 breaded onion rings at a time to the oil. Be sure to keep an eye on the oil temperature, adjusting the stove top heat accordingly. Cook for 45 seconds to 1 minute per side or until golden brown. Use tongs to transfer the cooked onion rings to drain on the paper towel and cooling rack-covered baking sheet. Once all the onion rings are cooked, serve immediately with your favorite dipping sauce.