1️⃣ Prepare the Fish:
Pat the fish fillets dry with paper towels to remove excess moisture. Lightly season the fillets with salt and pepper. Set them aside.

2️⃣ Mix the Batter:
In a mixing bowl, combine the flour, cornstarch, baking powder, salt, pepper, and garlic powder (if using). Gradually whisk in the cold sparkling water (or beer) until the batter becomes smooth and slightly thick. Be careful not to overmix to maintain the lightness of the batter.

3️⃣ Heat the Oil:
In a large skillet or deep fryer, heat vegetable oil to 350°F (175°C). Ensure the oil is deep enough to submerge the fish for even frying.

4️⃣ Coat the Fish:
Dredge each fish fillet lightly in flour, shaking off the excess. Then dip the floured fish into the batter, making sure it’s fully coated. Allow any excess batter to drip off before frying.

5️⃣ Fry the Fish:
Carefully place the coated fish into the hot oil, frying in small batches to avoid overcrowding. Cook each piece for 3-5 minutes per side, or until the batter turns golden brown and crispy. The fish should flake easily with a fork when done. Remove the fish with a slotted spoon and place on a paper towel-lined plate to drain excess oil.

6️⃣ Serve:
Serve the crispy fish immediately while hot, paired with tartar sauce, lemon wedges, and a side of coleslaw or fries for a complete meal.