For DIY sashimi get a small tuna or a slab of swordfish/marlin straight off the boat .Must have been caught that day .Instead of kikkoman and wasabi try it with lee&perrins and hot european style horseradish .Having spent 10 years eating seafood that was alive until 20 minutes before you eat it I am a little spoiled and do not very often eat in seafood places here .Best I can find is the fresh stuff that Ham and Bacon have flown in .If anyone can tell me where to get a fresh line caught king mackrel I will be eternally grateful .
Thanks for that .Tuna is now off the menu in my house .These large pelagics cannot be farmed easily and are an essential part of the food chain .If the Japanese are concerned about them then specimens this size must be as rare as a Tigers bits and bobs .