Preheat oven to 425 degrees F. Cut off the tough end of the asparagus and place them on a baking sheet. Roast the asparagus for 15-20 minutes until tender.

Mix Dashi, soy sauce and sugar in a bowl or a shallow pan that is large enough to soak asparagus.

Soak roasted asparagus in the prepared dashi sauce turning every now and then. Ideally soak them for 1 hour or longer, but if you don't have time 20 minutes will still make it a tasty dish.

Chill or serve right away with a sprinkle of Katsuobuhi.