Sprinkle the cod fillet with sake, let it sit for 5 minutes, and pat dry with a paper towel. Cut into 3 pieces.

Cut the silken tofu into bite-sized pieces. Slice 3/4 of the green onion diagonally into 1cm pieces and finely chop the remaining 1/4.

In a bowl, mix sugar, vinegar, miso, and ground sesame. Add the finely chopped green onion to create the miso sauce.

In a pot, heat water and dashi powder until boiling. Add the cod and skim off any foam. Then add tofu, diagonally sliced green onion, and ginger. Simmer on low heat for 5-7 minutes.