What Is Sanmai Oroshi & How-To’s With Chef Yuji Haraguchi

Sanmai oroshi, or three-piece cutting, is an essential technique for Japanese chefs.  It means breaking down the fish into two fillets and the center cut with the skeleton.  Sounds simple but it takes good skills to do it right; the goal is to preserve the flavor and texture of the pristine fish by minimizing damage during the process. 

Chef Yuji Haraguchi, the owner of Okonomi/Yuji Ramen and Osakana in New York, teaches you how.   

Yuji’s passion for seafood goes above and beyond.  His ambition and curiosity brought him to the U.S. in 2009 and he found a job at True World Foods, one of the largest wholesale distributors of fresh and frozen seafood in North America. During his career at the company, he gained a deep understanding of seafood and the restaurant industry.  Also, he found his mission to communicate the importance of sustainable seafood to the world through the traditional Japanese seafood diet.  

In 2014, Yuji opened Okonomi (daytime) /Yuji Ramen (at night) https://www.okonomibk.com/ in Williamsburg, Brooklyn to offer local, seasonal seafood dishes with Japanese hospitality omotenashi (wholehearted care without expecting returns).  In 2016, he founded a Japanese-style fish market Osakana https://www.osakana.nyc/ to help people to enjoy making high-quality sushi and sashimi at home by offering sushi-grade fish and educational classes.  

At the core of his mission is the Japanese mottainai philosophy, which essentially means “it is too precious to throw out”.  Sanmai oroshi represents this mindset.  A well-sharpened knife and good skills can increase the value of each piece.  For example, instead of discarding it, the bony center part can be used for stock or making umami-rich crunchy snacks by frying them.  In the case of tuna, the meat scraped from the bones is called nakaochi and connoisseurs ask for it at sushi restaurants in Japan.  


What Knife To Use For Sanmai Oroshi

Traditionally, the knife used for sanmai oroshi is deba but Chef Yuji developed his own way to break down fish while working in western kitchens in America.  He uses gyuto and scissors for this article instead.  

Gyuto is the Japanese equivalent of the classic western chef’s knife and it is used to cut everything from meats to vegetables.  (Santoku is another versatile Japanese knife with the added superior function of vegetable cutting and is popular among home cooks).    

Whereas deba’s hefty weight can make the cutting task easier, gyuto’s blade is thinner and more flexible than deba’s.  That is why Chef Yuji prefers using gyuto for sanmai oroshi.  

“If the fish is over 10 pounds, you need a deba, since the bones are too big to cut with scissors,“ he says.  

The chef also emphasizes that it is very important to understand the structure of fish to break down the fish smoothly.  Be sure to know where the bones are and align the knife with them accordingly.  


Removing the head

  1. Locate where the bones start by feeling along the backbones of the fish.
  2. Cut the collar from where the bone starts.  Move the blade towards the belly but go only as deep as you hit the ribs.  Once you hit the ribs, lighten the pressure as you cut the belly to avoid damaging the guts underneath. 
  3. Repeat this process on the other side.  
  4. Remove the guts.
  5. Gently cut the head off from the body.


Filleting the Meat

During this process, make sure that the tail remains attached to the body to keep your hands safe.  Also, only use the tip of the blade (the first third of the edge).  

  1. Cut the belly skin.  Pull your knife gently through the belly, using the bone along the belly as a guide.  The knife must stay parallel to the spine.
  2. Gently cut through the meat inside the belly skin in pulling motions.  
  3. Stop when you hit the ribs.
  4. Rotate the fish and cut the backside.  Use the backbones as a guide—slide your knife on the bones as you press the blade onto the cutting board. 
  5. Continue cutting towards the ribs in pulling motions and stop when you hit the ribs.
  6. Cut the filet off from the tail.
  7. Separate the filet and the middle part of the fish with scissors.


Preparing a fillet for sashimi

Sakudori is the process of preparing a fillet into a saku block (a block of boneless, skinless and bloodline-less fish meat) ready for sashimi. For saku blocks, the fish meat must be of the right thickness on all sides.

  1. Remove the ribs.  First, gently run the backside of the blade between the ribs and the pin bones.  
  2. Cut off the ribs.
  3. Repeat the process on the other side.  
  4. Use tweezers to remove the pin bones by pulling them in the same direction as they lie to minimize the damage to the meat.  
  5. Cut each filet in half.   
  6. Remove the skin by gently pulling the skin as you place the knife between the meat and the skin.  


Slicing Sashimi

If the saku block is thin, you can increase the surface area of sashimi by reducing the angle of the blade.  Start slicing from the heel of the blade and finish at the point of the blade in one pulling motion for a perfectly smooth texture.

Chef's Corner