Steps
1. Prepare the batter by mixing the cornflour, plain flour, salt and iced water.
2. Add 10ml of oil and sake to the mixture and whisk until everything is well combined.
3. Clean and chop the prawns into small pieces.
4. Dip the prawn pieces into the batter.
5. Heat the oil in a deep-fryer to 180°C and add the battered prawns until the top of the batter.
6. Turn over the prawns after they turn light golden brown.
7. Drain the tempura prawns on a plate covered with paper towel.
8. Serve with Japanese soy sauce if desired.