teriyaki tuna

I've bought Suji meat of Tuna. It's a part of fish meat in Japanese. I can't describe where it is in fish meat though, It's the meat beside the bone. This time, I got a suji part of Tuna. and cooked it with teriyaki sauce for my tomorrow lunch. the liquid were mixed with soy-sauce, mirin and sake. marinated the suji meat with the liquid for 30 minutes. wipe and saute the meat till brown and aside it. simmer away the liquid untill it become half. and put the meat back to the liquid and simmer away untill it become thick.