Heat the vegetable oil in a deep fryer or large, deep saucepan to 180°C (350°F).
Rinse the fish fillets under cold water and pat them dry with paper towels. Lightly dust with flour.
In a bowl, mix together the flour, baking powder, and a pinch of salt. Gradually whisk in the beer until the batter is smooth.
Dip the fish fillets into the batter, ensuring they are completely covered.
Carefully lower the fish into the hot oil and fry for 6-8 minutes, or until golden brown and crispy. Remove and drain on paper towels.
Increase the oil temperature to 190°C (375°F). Add the chips to the hot oil and fry for 5-7 minutes or until golden and crispy. Remove and drain on paper towels.
Season the chips with salt and serve with the fish and optional malt vinegar.