Serves: 8This is a light but flavoursome start to the evening. If you don't want to use crayfish, sliced scallops or simply thinly sliced fish fillets are a good substitute

The dashi or traditional Japanese fish stock which is the first part of the method is based on the recipe from Shizuo Tsuji’s definitive book, Japanese Cooking: A Simple Art. It is important to follow the instructions exactly. The strained bonito flakes can be used again, following the same procedure with new kelp to create secondary dashi (niban-dashi) for use in thick soups, and for adding flavour when cooking vegetables.

20g giant kelp (konbu)*, wiped with a damp coth
30g dried bonito flakes*
1 small raw crayfish tail (shell on), from a 550g crayfish
zest of 1 lemon
4 teaspoons Japanese soy sauce
1 purple kumara, peeled, diced 1cm, steamed or boiled in well-salted water until tender, drained and cooled
Green top of 1 spring onion, thinly sliced on the diagonal

Put 1 litre of water in a saucepan and add the kelp. Slowly heat, uncovered, so it reaches boiling point in about
10 minutes. Kelp emits a strong smell if it is boiled, so remove the kelp just before it boils. To make sure the kelp has added enough flavour to the water, insert your thumbnail into the fleshiest part of the kelp. If it is soft, remove and discard it. If the kelp is still tough, return to the saucepan, along with 1⁄4 cup cold water to keep it from boiling, for 1-2 minutes. Discard the kelp.

Bring the saucepan of water to a full boil. Add 1⁄4 cup cold water to bring the temperature down then immediately add all of the bonito flakes. Don’t stir.

Bring back to a full boil then immediately remove from the heat – if it’s allowed to boil the stock can become bitter and too strong. Set aside for 30 seconds then skim and strain through a very fine sieve. This is the dashi stock. Reserve.

Bring a saucepan of salted water to the boil then add the crayfish tail. Bring back to the boil and boil gently for 5 minutes or until cooked through. Remove the crayfish and allow to cool.

Using kitchen shears, cut the crayfish tail open lengthways along the top and bottom, taking care not
to cut the flesh. Remove the shell.

Slice the crayfish thinly. When ready to serve, bring the dashi stock to the boil then add the zest and soy sauce. Reduce the heat and simmer for a few minutes.

Divide the kumara and crayfish slices among 8 small warmed bowls. Cover with the hot dashi stock then sprinkle a few slices of spring onion on top. Serve immediately.

* Available from Asian food stores.

Wine - A Central Otago dry riesling.