Whip the egg whites until stiff and place them in the fridge.
Then whisk the egg yolk with 1 tsp salt and a dash of pepper.
Mix in 125 ml Jever, 125 ml water, 250 g flour, 50 g cornflour and ½ tsp baking powder.
Next, stir ice-cold water into the flour mixture until there are no lumps. Gently fold in the stiffened egg whites.
Place the batter in the fridge for half an hour.
Divide the fish fillet in the middle and heat oil in a pan to around 180°C. Dip the fish in the coating and cook it in the oil for around 6 minutes until both sides are golden brown.
Serve the fish with a bottle of Jever, a bread roll with remoulade or a potato salad.