Prepare a light batter using 300 g plain flour, 2 tbsp potato flour, a pinch of salt, 250 ml light beer or lager and 2 eggs. Stir in 1 tbsp oil. Use a two-pronged fork to dip fruit in the batter, allowing the excess batter to drain off. Heat the vegetable oil to 190°C to deep-fry the fritters. Drain, then turn in caster sugar.
Peel and cut the fruit, removing pips or stones. Drain well on kitchen paper, then dip into the batter.
Deep-fry the fritters for 2-3 minutes until crisp and golden. Once fried, drain well on kitchen paper.
Turn the fritters in caster sugar, giving them an even coating. Serve fritters immediately.