Instructions

• Slice 1 large sweet onion into 1/4-inch-thick rings and separate the rings carefully.
• In a shallow dish, whisk together 1 cup all-purpose flour, 1 teaspoon baking powder, and 1 teaspoon salt.
• In a second shallow dish, whisk 1 cup buttermilk and 1 large egg until smooth.
• Place 1 cup panko breadcrumbs in a third shallow dish.
• Pour 1 quart vegetable oil into a deep-fryer or a large, heavy saucepan and heat to 365°F, using a thermometer to monitor the temperature.
• Working one ring at a time and in batches to avoid overcrowding, dredge each onion ring in the flour mixture and shake off excess, dip it into the buttermilk mixture, then press both sides into the panko breadcrumbs to coat. Place coated rings on a wire rack.
• When the oil is at 365°F, fry the onion rings in batches until golden brown, about 2–3 minutes total per batch, turning once halfway through cooking. Do not overcrowd the pan; adjust heat as needed to maintain 365°F.
• Remove fried rings with a slotted spoon or tongs and drain briefly on paper towels or a wire rack. Repeat with remaining rings.
• Serve the onion rings immediately.