Instructions

• Peel the 1 large sweet or yellow onion and slice it into 1/2-inch-thick rings; separate the rings and set them aside.
• In a medium bowl, whisk together 1 cup milk and 1 Tbsp white vinegar; let sit 5 minutes. Whisk in 1/2 cup sour cream until smooth — this is the wet batter.
• In a separate bowl, whisk together 1 cup all-purpose flour, 1/2 Tbsp salt, 1/4 tsp black pepper, and 1 tsp garlic powder — this is the dry coating.
• In a Dutch oven (or deep fryer), add about 1 inch of oil (or enough to cover the rings) and heat over medium. Use a thermometer and bring the oil to 375°F before frying.
• Coat the rings: working a few at a time, dip each ring into the wet batter, then dredge in the dry coating. Dip the floured ring a second time in the wet batter and dredge again in the dry coating to double-batter. Use a fork to transfer rings between bowls if you prefer. Place the finished rings on a plate in a single layer until ready to fry.
• Fry in batches so you do not overcrowd the oil. When the oil is at 375°F, carefully add 3–4 double-battered rings in a single layer. Fry about 3 minutes total, flipping once halfway through, until the exterior is crisp and light golden brown. Return oil to 375°F between batches if it cools.
• Use a slotted spoon or tongs to transfer cooked rings to a paper towel-lined plate to drain.
• Serve the onion rings hot.