This is called "namerou" なめろう. It is a type of "tataki" たたき or Japanese style tartar type preparation. I am not sure of the origin of the name but "nameru" なめる means "to lick". This dish was said to be made by a fisherman on the boat, simialr to the origin of "okizuke" 沖漬け. The fish used in this dish is usually a blue-white shiny skinned fish, "hikarimono" ひかりもの, such as mackerel. Tuna is not commonly used but I made this with the frozen tuna.
I used about 1/3 saku since I made three different dishes shown here. I first roughly chopped the tuna into small cubes, sliced scallion, minced perilla and fresh ginger (amounts all arbitrary). I added half a tsp of red miso paste to start. I minced (or "tataku", meaning to bang or hit with a knife blade) all these together until it became sticky and well mixed but still retained some shape. I tasted it and added a little more miso to finish. If this becomes too stiff, you could add a small amount of sake to make it the right consistency, which I did not need to do. This was a great success! Because of the many flavors especially the miso and the nice consistency, it was perfect to nibble while sipping cold sake. If you were not told, you would not be able to tell that this was made of frozen yellow-fin tuna.
The third tuna dish is our usual stand-by and is nothing new; just classic "yamakake" やまかけ.
We think, even for frozen saku of yellow-fin tuna, these three dishes I made tonight were quite good (I know my standards may have fallen substantially compared to those of Japanese food connoisseurs out there, especially a few in Tokyo).