Slowly add the sparkling water, whisking until smooth. The batter should be thick but pourable. Fry the Cod: Heat vegetable oil in a deep skillet or fryer to 350°F (175°C). Dip the cod fillets ...

Put the potatoes into the fryer and allow them to fry gently for about 8-10 minutes ... Season the fish and dust lightly with flour; this enables the batter to stick to the fish.