Making Dashi

Dashi is the Japanese stock behind miso soup and many sauces. Soak a 10 cm piece of kombu in 1 litre of water for 30 minutes or overnight. Heat it slowly and take the kombu out just before it boils; boiling makes it slimy and bitter. Bring the water to a boil, turn off the heat and add a big handful of bonito flakes, about 20 g. Let them sink, wait two minutes, then strain through a cloth without squeezing. For vegan dashi, soak kombu with dried shiitake overnight instead.