Cut the potatoes in the shape you like to have them. Rinse them in cold water and drain away the water until they are dry.
If you like to prepare the potatoes in the oven preheat the oven with electrical heat at 200 degrees Celsius. Place the potatoes on a baking sheet and pour 2 tablespoons of sunflower oil on them. Place them in the middle of the oven and turn them from time to time.
If you like to fry the potatoes, preheat a frying pan with 2 tablespoons of sunflower oil and fry the potatoes until they have a crispy surface.
In a deep plate mix the beer, flour and baking powder, let it rest for 10 minutes.
Salt and pepper both sides of the fish fillets, this way it drains out the water nicely.
Dip the fish fillets in flour on both sides.
Heat up the sunflower oil and the butter in a frying pan.
Dip the fish fillets in the batter on both sides and fry them in the frying pan until the surface is nicely brown and crispy.
If you fried the potatoes, fry them gently in another frying pan until they are warm. If you made them in the oven take them out from the oven.
Serve the fish and chips warm together with the citron and your choice of sauce on the side.