To make a good tempura you must use icy water and, another trick I picked up from my mother, add a little Japanese mayonnaise to the batter — this makes the consistency delightfully crisp.
- To make dipping sauce mix water, soy sauce, mirin, sugar and dashi powder in a small saucepan and boil for 2 minutes.
- Reduce the heat and simmer a further 3 minutes. Remove from the heat and set aside.
- To make tempura batter, beat the egg, salt and mayonnaise in a bowl, then add ice-cold water.
- Add half of the flour and mix well. Add the rest of the flour and mix only a couple of times. The key is not to overmix — some flour left on top of the batter is good.
- Heat oil in a wok or deep fryer to 180C.
- Dust prawns, vegetables and nori with flour and dip lightly into the tempura batter, deep fry until crispy.
- Remove tempura and place on a paper towel to drain excess oil. Serve immediately with dipping sauce.
Tip: Prepare everything in advance, deep fry the tempura at the very end, and eat it as soon as you can!