HOW TO FILLET A SALMON OR ANY OTHER FISH
The first cut you want to make is right behind the gill plate ... cut perpendicular to the length of the fish down to the backbone. Next, turn the knife blade parallel to the length of the fish and insert level to your cutting surface until you feel the tip of the knife hit the backbone (see pic on right). Next, carefully cut down the length of the fish, keep the knife tip on the backbone ... if you lose contact with it, stop cutting and reposition the tip on the backbone before proceeding.
When you reach an area just in front of the adipose fin, gently push down on the knife handle to lift the blade just over the backbone and then press down and through the fish as shown in this picture on the left. Once through the fish, pull the knife towards the tail completing your initial cut.
Your next step is to return to the head end of the fish and make a shallow cut through the line of pinbones that extend from the backbone ... be careful not to cut too deep and cut through the ribs. Some people start at the tail end of this cut ... that works too ... whatever is easiest for you ... just make sure to stay away from those ribs ... recovering from a goof here can be difficult.
The next step is to lay the knife at a really shallow angle to the ribcage and cut along the ribs ... cutting on the exact same lines as the rib bones lay. Be careful not to cut a too steep of an angle ... you'll cut through the ribs. Pull the fillet back with your hand as you cut. Continue until you run out of meat in the belly area ... then make a cut through any rib bones that may still be attached to the belly area. You should now have a complete fillet on one side still attached to the belly.
Your next step is to turn the fish over and face it the other direction. Make sure to place the fillet you cut from the other side under the fish as if it was still a whole fish. Notice the positioning of the fish in this picture compared to those above. Then you simply repeat the steps we took you though above.
You'll see as we make the cut through the pinbones on this side, we start from the tail area and work back to the head ... as we said before, some people like to do this ... we find it easier to do it this way on this side as we find it easier to keep the knife at a shallow angle while pulling towards me.
Cutting along the rib bones on the second side ... this can be especially tough if dealing with a mature hen ... this is where a non-slip mat pays off big and you'll find it necessary to keep the fish from moving around and rolling off the egg skeins. You'll see when you try it!
When you complete the filleting on this side of the fish, you will still have an area around the anal fin and vent that has to be cut away from the fillet section ... we find it easiest to lift the tail as shown and cut through the skin and flesh that is still attached to the fillet.
This is your finished product.
You can cut through the belly meat on each side to produce two separate fillets with a piece of belly meat ... or leave it as is for your next party!
Enjoy, and remember to only keep what you need! Carefully return the rest back to the river to help preserve our fishing opportunities!