This was an on-the-fly recipe I came up with one evening. We had our usual frozen yellow fin tuna block thawed. Although I have made quite a few dishes designed to make this low-quality tuna sashimi palatable, I was pressed with time and came up with this quick dish.
This is "shimo-furi" 霜降りor very rare tuna steak with the surface seared in with a small amount of oil in a frying pan. I made a sauce which was mixture of aged balsamic vinegar and soy sauce in the same pan.
This was not bad and went well with the red wine (I am sure it was California cab) rather well.