Cutting a block of raw fish was intimidating for the longest time for me. I know for a fact that I am still not doing it like the pros because 1) I don't cut with a sashimi knife and 2) I've only cut raw fish about 5 times.
Cutting, plating and serving sashimi at home provides a splash of unexpected luxury which is always welcome in my book.
Because I don't have a sashimi knife, I use the longest knife I own that is not serrated. I also always sharpen the knife right before I cut to ensure that I have a very fine, clean edge. Sharpening the entire edge of your knife is very important when cutting raw fish so get your water stones soaked up for an intense session.
I will be demonstrating with a wild salmon sashimi block. Notice the diagonal lines running through the flesh. The goal is to slice while intersecting these lines at a 90 degree angle.
Once, you've established the lines, take note that you must cut the flesh in one long stroke. You do not want to cut sashimi like it's a well-done steak or tough baguette - no back and forth sawing here.
Understanding that you have to cut each slice in one long stroke means that you will have to apply just the right amount of pressure to execute a clean cut. The first few times I did this I failed, leaving a sinewy strand or two uncut.
After practicing a few times, you will get the hang of it. You will feel how much pressure must be applied to cut through an entire slice in one stroke.
Here's a video.
I noticed that even though I am not even close to a pro sashimi cutter, the results are quite satisfactory. Having a temaki party with fish you just cut is fun and probably about 10 times less expensive than going out.
Temaki party shots: