Begin by heating oil in a deep frying pan or a fryer over medium heat until it reaches 350°F (175°C).

In a large mixing bowl, whisk together gluten-free all-purpose flour, baking powder, salt, and black pepper until combined.

Gradually add in sparkling water while continuously whisking to create a light and airy batter.

Pat the white fish fillets dry with paper towels to ensure the batter adheres well.

Dip each fillet into the prepared batter, allowing the excess to drip off before frying.

Carefully place the battered fish into the hot oil in batches, frying each side for 4-6 minutes until golden brown.

Remove the cooked fish using a slotted spoon and drain on paper towels.

Serve immediately alongside fresh coleslaw or your favorite dipping sauce.