This is a super-easy soup to make, especially as you can use store-bought chicken broth. Leave the stock in the freezer until very cold – the colder, the better on a hot day. You can use cooked buckwheat instead of the soba noodles; and could also replace the prawns with chunks of cooked chicken with the skin removed.
1.6L homemade or good-quality shop-bought chicken stock
15g ginger, thinly sliced
60ml rice wine vinegar, plus extra to serve
40ml soy sauce, plus extra to serve
400g soba noodles
30ml sesame oil
8 king prawns, peeled and cooked
½ nashi pear or bosc pear, peeled, cored and julienned just before serving to avoid discolouring
70g cucumber, halved, deseeded and julienned
2 hard-boiled eggs, peeled and halved
10g spring onion, white part only, finely chopped
20g toasted sesame seeds
1. Combine stock and ginger in a heavy-based saucepan and bring to the boil over medium heat. Remove from the heat and add rice wine vinegar and soy sauce. Allow to cool before pouring into a freezer-safe bowl and placing into the freezer to chill for an hour.
2. Bring a large, heavy-based saucepan of water to the boil, add the noodles and cook for 3 minutes or until just cooked through. Drain and refresh multiple times in cold water until the noodles are cold. Drain well, then toss with sesame oil to prevent them from sticking together. Refrigerate until well chilled.
3. Divide noodles among 4 bowls, ladle over the chilled broth, then garnish with prawns, pear, cucumber, hard-boiled egg and spring onion before scattering with toasted sesame seeds. Serve with extra rice wine vinegar, soy sauce and wasabi so that everyone can season to taste.