Prawn and Sweet Onion Tempura


Preparation info

  • Difficulty


  • Serves


Appears in

My Asian Kitchen

My Asian Kitchen

By Jennifer Joyce

Published 2018

  • About

Tempura sounds straightforward, but getting the batter right can be tricky. After many so-so results, I have finally come up with a failproof recipe. A mix of regular and fine flours, such as cornflour, blended with ice-cold soda water creates a blistering coating. The batter should never be thick – it only needs to lightly coat the vegetables or prawns, which should be sizzled to a pale colour, not browned.

Prep 10 minutes
Cook 10 minutes


  • 3 sweet onions
  • 250 ml ( fl oz) ice-cold soda water
  • 1 egg
  • 90 g 3 oz) cornflour
  • 90 g 3 oz) plain flour, plus extra for dredging
  • vegetable oil, for frying
  • 8 very large raw peeled prawns with tails, deveined

Lime Ponzu Sauce

  • 45 ml ( fl oz) Japanese light soy sauce
  • 2 tbsp lime juice
  • 1 tbsp caster sugar


Peel the onions, keeping the roots intact. Slice them about 1 cm (½ inch) thick and try to keep in one piece.

Mix the lime ponzu sauce ingredients together in a small bowl and set aside.

In a large mixing bowl, mix the soda water and egg. Place the flours in another bowl. Scatter some extra plain flour onto a shallow plate and set aside.

Heat the oil in a wok or deep medium saucepan until it reaches 180–190°C (350–375°F) or when a small piece of bread instantly sizzles. I like to use a sugar thermometer to guarantee a steady temperature. If the oil is too hot, the tempura will burn and if it’s too low, it will become greasy.

While the oil is heating, make the batter. Pour the dry ingredients into the wet and stir with chopsticks. Stir just enough so that it combines, but is still shaggy and lumpy. Dust the prawns and onions with the extra flour and then dip into the batter. Fry about six or seven pieces at a time and cook until golden, about 3–4 minutes. Drain on a baking tray topped with a rack. The rack maintains their crisp finish (versus paper towels, which make them soggy).

Serve the tempura immediately with the lime ponzu sauce.