Q When I try frying tempura prawns, the batter either falls off or is uneven. I use supermarket tempura flour mixes and dip the battered prawns only in hot oil. I've been told that placing ice cubes in the batter to lower the temperature helps. How can I fry good tempura prawns akin to those served in Japanese restaurants?

A Tempura mixes sometimes come with unnecessary additives, so you're better off making your own batter.

The basic proportions are 1 egg to about 140ml icy-cold water to about 110g cake flour. Some cooks like to use a blend of flour and cornstarch instead of just flour.

Beat the egg with the water until blended, then add the flour and stir briefly with chopsticks until just barely mixed - it should be very lumpy. Small lumps of unmixed flour help to give a lighter, more open fried batter texture. Always add flour to the liquid, and not vice versa.

Japan has regional variations in batter style, so feel free to alter the flour, egg and water proportions to get the consistency you like. More delicate items such as prawns and fish need thin batter whereas other ingredients such as sweet potato and thick onion slices suit a thicker batter.

Shell the prawns, leaving tails and the adjacent first section of shell on. Make a shallow cut along each prawn's underside - where the legs were - to prevent it curling up when cooked. Wash and pat prawns completely dry.

Let your oil (canola or sunflower oils work well) heat to a temperature of about 180 deg C, at which point it will shimmer and start to give off a light haze.

Japanese tempura restaurants often blend a small percentage of sesame oil with their frying oil for fragrance.

If you wish, very lightly dust the prawns with potato starch to help the batter cling. Dip your prawns and lower them into the oil.

Fry a few at a time without crowding. If you feel up to it, dip your frying chopstick tips into the batter and flick droplets onto the prawns as they fry, to build up a lacy, irregular crispy coat. This technique is poetically called 'making flowers' in Japan.

And here's a note for all of you who write in to ask for recipes for deep-fried things that stay crunchy for hours: Tempura, like so many fried items, is meant to be made, served and eaten immediately.

Environmental humidity is no respecter of lifestyle demands and can make tempura sog out in as little as 30 minutes.

This article was first published in The Sunday Times on Mar 16, 2008.