Nori no Tsukudani is a popular Japanese rice topping that offers a rich, savory taste of the sea. Although you might not be familiar with the black color of nori seaweed, you will be pleasantly surprised by its rich flavor once you try it.
Tear nori seaweed into pieces and put them in a pot. Add dashi and seasonings (sake, mirin, sugar, and soy sauce) to the pot, and let it sit for a few minutes until the nori softens.
Heat the pot over medium heat and simmer, stirring occasionally with chopsticks or a spatula until almost all of the liquid has evaporated.
Notes
You can store it in the refrigerator for up to a week.