Make the tartar sauce: Combine all tartar sauce ingredients in a bowl. Mix well, season to taste, and refrigerate.
Cook the fries: Fry or prepare your regular fries until golden and crispy. Season immediately with salt and keep warm.
Prepare the fish: Pat the fish dry and cut into strips. Lightly dust each piece with flour and shake off the excess.
Make the batter: Whisk together flour, starch, baking powder, salt, paprika, and curry powder. Gradually whisk in very cold soda water until smooth and thick enough to coat the fish.
Heat the oil: Heat neutral frying oil to 350°F–365°F (175°C–185°C).
Coat the fish: Dip each floured piece of fish into the batter, allowing excess batter to drip off.
Fry: Carefully fry the fish in small batches for approximately 5–6 minutes, until deeply golden, crispy, and cooked through.
Drain: Transfer the fried fish to a wire rack or paper towel-lined tray.
Serve: Plate the hot crispy fish with fries, homemade tartar sauce, and fresh lemon wedges.