Prepare the Dry Ingredients: In a large mixing bowl, whisk together the flour, cornstarch, baking powder, salt, pepper, and paprika (if using).
Add Sparkling Water: Slowly pour the sparkling water into the dry mixture, stirring gently until the batter is smooth and slightly lumpy. Be careful not to over-mix—this helps achieve a light, crispy texture.
Heat the Oil: Heat about 2-3 inches of oil in a deep fryer or large, heavy-bottomed pot to 350°F (175°C). The oil should be hot enough that a small drop of batter sizzles when dropped in.
Coat Your Ingredients: Dip fish fillets, chicken tenders, vegetables, or your choice of protein/vegetables into the batter. Make sure they’re well-coated, but not overloaded with batter.
Fry Until Golden: Gently place the battered ingredients into the hot oil. Fry in batches, turning occasionally until they are golden brown and crispy—this should take about 4-5 minutes.
Drain and Serve: Remove from the oil and drain on a paper towel-lined plate to remove excess oil. Serve immediately with your favorite sides and dipping sauces.