Soba noodle soup with prawn tempura (Tenpura soba)

1. Peel the prawns, leaving the tails on, score the bellies in 3-4 places and pat dry.

2. For the soup, bring the dashi to the boil with the soy sauce and mirin and keep warm.

3. Mix the ice-cold water with the egg, sprinkle in the flour and barely stir with chopsticks; heat the oil to 175 °C.

4. Holding the prawns by the tail, dip them in the batter and fry for 2-3 minutes until pale and crisp, then drain on a rack.

5. Cook the soba for the time on the packet, drain, rinse quickly in cold water, then reheat briefly in hot water.

6. Divide the noodles between hot bowls, pour over the soup and top with the prawns and spring onion; serve at once.

Tip: Toshikoshi soba is a must on New Year's Eve in Tokyo: the long noodles symbolise a long life. Put the tempura on the soup only just before serving, so part of the batter stays crisp.