Rinse the kombu under cool running water for 20 seconds, rubbing it gently, then pat dry with a doth and place in a saucepan with
Place the dried shiitake in a bowl of tepid water and mix them around with your hand for 30 seconds to dislodge any grit. Leave them for a minute, then add to the saucepan with the kombu, discarding the soaking water.
Break or cut the stalks from the fresh shiitake and add these to the pan, then slice the caps thinly and set aside. Peel all the ginger; slice half very thinly and add to the pan, then finely julienne the rest and set aside.
Slice the leek into 5mm rounds and add two-thirds to the pan. Slowly bring to just below boiling point – but don’t let it actually come to the boil. Turn down to a simmer and cook for 8 minutes, then turn the heat off and cover with a lid. Leave to sit for 30 minutes.
Place the sea vegetables in a small bowl and pour over a cupful of water. Strain the soup into a clean pan and add the sliced fresh shiitake caps, ginger julienne, remaining leek, mirin and soy sauce.
Take the dried shiitake, which will have swollen up now, and slice them very thinly, then add these to the pan, discarding the stalks (which can sometimes be woody). Bring the soup to a simmer and cook for 3 minutes. Drain the soaked sea vegetables.
Ladle the soup into 4 bowls, adding some of the sea vegetables as you go. Drizzle the sesame oil on top just as you serve it.
© 2007 Peter Gordon. All rights reserved.