The Preparation
Heat oil to 375°F in a deep pot or Dutch oven.
Whisk together flour, cornstarch, baking powder, salt, pepper, garlic powder, and paprika.
Stir in cold sparkling water or beer until just combined — batter should be thin and slightly lumpy.
Dip onion slices into the batter, letting excess drip off.
Fry in batches for 2-3 minutes per side until golden and crispy.
Drain on a wire rack set over paper towels.
Season with salt immediately after frying.
