This is hirame (flounder) cut at the chef’s counter /a la minute/ and I call C.C. or known as counter cut.
You rarely see whole fish cut right in front of your own eyes at a sushi restaurant. Many people speak about their experiences in Japan with fish jumping, or shrimp flying but I’ve never seen it before. I have seen Ise Ebi, a Japanese lobster served after it’s tail was cut and the fresh raw meat placed back into the lobsters body. But I saw this outside of Japan and maybe once at a ryokan at the seaside.
I used a ponzu (sauce) to extract extra flavors given the texture of the flounder’s leading edge is chewy enough. The muscle at the topside of the fish that motors the top fin has done its job during the fishes life. Hence a muscle and chewy but it has a wonderful crunch to it, and the ponzu’s citrus based sauce with hints of spice and fresh spring onion gives it a soothing and satisfying contrast. By the way in Japan they call the leading edge Engawa and in France they throw away.
How to make Ponzu: asatsuki neggi, mirin, togarashi, sudachi, kabotsu and shoyu.