Kozuyu (Aizu dried scallop soup)

Step 1: Put the 1 oz dried scallops (hotate kaibashira), 3 dried shiitake mushrooms and ⅛ oz dried wood ear mushrooms (kikurage) in separate bowls and divide the 4 ¼ cups hot water between them, using about 600 ml for the scallops and the rest for the mushrooms. Soak for 30 minutes, until the scallops break apart when pressed. For the deepest flavour, soak the scallops overnight in the fridge instead.

Step 2: While they soak, cut the 7 oz taro (satoimo), 1 carrot and 3 ½ oz shirataki (konjac noodles). Drop the shirataki into boiling water for 2 minutes and drain, to take away the smell.

Step 3: Lift out the mushrooms, squeeze them gently over their bowl and slice them into small pieces, discarding the hard shiitake stems. Shred the soft scallops with your fingers. Strain all the soaking water through a fine sieve into a pot; you should have about 900 ml (top up with water if needed).

Step 4: Add the scallops, mushrooms, taro and carrot to the pot. Bring to a simmer over a medium heat and skim off any foam.

Step 5: Lower the heat so the surface barely trembles and cook for 10 minutes, until the taro and carrot are just tender. Common mistake: letting the soup boil. A rolling boil breaks up the taro and turns the clear stock cloudy.

Step 6: Add the shirataki, ⅓ oz small dried wheat gluten balls (mame-fu) (if using), 1 tbsp sake, 1 ½ tbsp light soy sauce (usukuchi) and ½ tsp salt. Leave out the sake or replace it with water for an alcohol-free soup. Simmer for 3 minutes.

Step 7: Add the 1 ⅜ oz frozen edamame beans or ginkgo nuts and warm through for 1 minute. Taste; the soup should be lightly salted, like a good stock. Serve in small, shallow bowls.

Step 8: To make ahead, cool the soup quickly, refrigerate within 2 hours and keep for up to 2 days. Reheat gently until steaming; the flavour improves overnight.