Kelp: A good dried kelp--one that gets soft when cooked and is therefore good for eating. "Hidaka" 日高 kelp is especially desirable, since it gets softer more quickly than other types of kelp such as Rausu 羅臼 or Rishiri 利尻 kelp. I soaked a 5-6 inch long piece of dried "Hidaka" kelp in water until it returned to its "natural state" and became pliable (30 minutes to 1 hour). I used 4 strips to make 8 good sized rolls. I trimmed the ragged ends to make a nice rectangular piece. I reserved the soaking liquid.
Kanpyo: This is mostly to tie up the rolls so they don't unravel but it does have some texture and taste. I washed and then massaged several pieces of kanpyo with salt and washed again. I soaked it in water for 30 minutes to one hour but did not cook.
Salmon: I used fresh salmon. I cut the fillet into 1/2 inch wide strips with the skin left on. I trimmed the end to make it fit the width of the kelp.
I rolled the kelp around the salmon strip in the center and tied it off in two places using the kanpyou as shown below (this pictures is after cooking). I placed all 4 rolls in a shallow pan in which they fit snuggly (I used a square Pyrex baking pan with a glass lid). I then poured in the kelp soaking liquid. Since I also had a soaking liquid left over from rehydrating dried shiitake mushrooms (used in another dish), and the mushrooms had imparted some good flavor to the liquid I also added that. I added sake (2-3 tbs) as well. The kelp rolls should be just covered with water. I simmered it with the lid on for 1 hour or until the kelp is soft.
Seasoning: The seasoning is essentially sweet and salty (soy sauce) which is a typical Japanese seasoning. As a rule, the "sweet" of the seasoning is added first. So I added sugar (1 tsp) over the rolls and let it simmer for 5 minutes with an otoshibuta 落 とし蓋. I then added more sugar (1 tsp) and soy sauce (1 tbs) and simmered it for 10-15 minutes. At the end of cooking, the liquid was reduced in half. At the very end, I added mirin (2 tsp) and soy sauce (2 tsp) for a fresh taste. Again, the seasoning is up to your liking; you could add more sugar, mirin and soy sauce. I did not want to season it too strongly. I let it cool in the cooking liquid. The picture above shows it after it cooled and was ready to be cut.
The standard way is to cut the roll in half to make two rolls as seen above but that would have resulted in pieces that were too big to eat in one bite. For a drinking snack, I cut the individual rolls into three smaller pieces as seen in the first picture.
The kelp is soft but not mushy. It has a lovely unctuous mouth feel. The salmon is lusciously tender with a slight sweetness and mild soy sauce flavor. It is hard to imagine how a dish this good could be transformed into the product sold commercially. While my wife did not dislike the commercial product it was not the first thing she chose from the New Year's box. She liked this one so much it could "star" as a drinking snack. Maybe this dish "isn't just for New Year anymore."