Cut the fish fillets into individual portions. Pat them dry thoroughly with paper towels. Season both sides with salt and pepper.
Heat a deep fryer or heavy-bottomed pot with vegetable oil to 375°F (190°C).
In a large mixing bowl, combine the flour, cornstarch, AB’s A Rub, and baking powder. Gradually whisk in the Ginger Ale until the batter is smooth but not overmixed.
Dip each fish fillet into the batter, allowing excess to drip off. Carefully lower into the hot oil.
Fry for 3–4 minutes per side until golden brown, crispy, and cooked through. Remove and drain on a wire rack placed over a paper towel-lined tray.
Serve hot with steak fries, lemon wedges, malt vinegar, and tartar sauce on the side.