Peel the onions and slice into 1/4- to 3/8-inch thick rounds. Separate into individual rings and set on a tray. Remove any small inner rings (reserve for snacking). Pat rings dry with paper towels.

Dust rings

Place 1/4 cup flour in a shallow bowl or tray. Lightly toss onion rings in the flour to coat; shake off excess. This helps the batter adhere.

Make beer batter

In a medium bowl, whisk together 1 1/2 cups flour, 1/4 cup cornstarch, 1 tsp baking powder, 1 tsp kosher salt, 1 tsp black pepper, 1 tsp paprika and 1/4 tsp cayenne. In a separate small bowl, beat the egg. Pour the egg into the dry mix, then gradually whisk in 12 fl oz of cold beer until a smooth, slightly thick but fluid batter forms. If the batter seems too thick, add up to 2 tbsp ice water to reach a texture that coats the back of a spoon. Do not overmix — a few small lumps are fine. Keep batter cold by placing bowl in a larger bowl with ice, if desired.

Heat oil

Pour vegetable oil into a deep heavy pot or deep fryer to a depth of at least 2.5 inches (about 1 liter). Heat oil to 375°F (190°C). If you don't have a thermometer, test by dropping a teaspoon of batter: it should sizzle and float up immediately and brown in about 30–45 seconds.

Batter and fry

Working in small batches (4–6 rings at a time, depending on pot size), dredge the floured rings briefly in the batter, allowing excess to drip back into the bowl. Gently lower rings into hot oil using a slotted spoon or spider. Fry, turning occasionally, until golden brown and crisp, about 2 to 3 minutes per batch. Do not overcrowd the pot; overcrowding drops oil temperature.

Drain and season

Use a slotted spoon to transfer cooked rings to a wire rack set over a baking sheet or to paper towels to drain. Immediately sprinkle with a light pinch of kosher salt while still hot. Keep finished batches loosely tented in a warm oven at 200°F (95°C) while you fry remaining rings so they stay crisp.

Serve

Serve onion rings hot alongside the Southern comeback sauce for dipping.

Southern Comeback Sauce

Combine ingredients

In a small bowl, whisk together 1/2 cup mayonnaise, 2 tbsp ketchup, 1 tsp prepared horseradish, 1 tsp hot sauce, 1 tsp apple cider vinegar and 1/2 tsp Worcestershire sauce until smooth.

Season and finish

Stir in 1/2 tsp smoked paprika, 1/4 tsp garlic powder, 1/4 tsp onion powder, 1/4 tsp salt, 1/8 tsp black pepper, 1 tbsp finely chopped pickle and 1 tbsp finely chopped green onion (if using). Taste and adjust seasoning — add more hot sauce or horseradish for heat, or more vinegar for tang.

Chill

Cover and refrigerate the sauce for at least 30 minutes to let flavors meld. Bring to near-room temperature before serving if it has been chilled very cold; a short stir before serving ensures even texture.