Kombu seaweed, dry. As you can find it in all Asian markets. On the beach, they are very long, several metres. They cut bands of 50 cm to dry them. Then they are sold like that at markets or pre-cut for convenient packaging. It’s easy to cut with scissors.
It is used in combination with dry fish to make dashi, the Japanese all purpose stock (click on text) :
But you can also make a pure kombu dashi. The taste is of course different from the fish versions. So it is used for different dishes.
That’s a convenient substitute to classic dashi stock for vegan or any diet that excludes fish.
Kombu dashi (recipes)
-Take a piece of kombu seaweed (a square of 25 cm for 1/2 liter or 2 cups). Either you pass it 2 seconds under tap water, or wipe it with a wet kitchen paper, in order to clean away the white dust (salt) around it. To release more flavor quicker, you can make cuts in it all around.
First round :
-Put it in a sauce pan with the water. Slowly bring to boil. Cut the heat. Wait 2 hours. Take your stock.
Second round :-Add more water. Keep in the fridge overnight. You get a second batch of stock.
Third round :
-Cut the softened kombu and use it as an ingredient or a topping (like you’d use mushrooms, many recipes possible).
Other recipe, by cold processs :
Same as before, but no cooking is necessary. Let the kombu soak in water overnight, in the fridge. You can eat it raw too.
It’s not time consuming to prepare it. Just think in advance.
I don’t think you can store it a long time. If it is boiled, it’s OK 2-3 days in the fridge. If it is raw, rehydrated of course. I’d use it in the day, even refrigerated.