Originally Posted by deanster

It really all depends on what kind of tuna it actually is--is it ahi ahi (yellow fin)? Ahi is the bomb, the deep red flesh you can use for sushi/sashimi (if purchased fresh and not frozen) and is best seared quickly on each side and served rare, with possibly a crust of seeds or fresh cracked pepper and served with a light sauce--no need for marinating, the flesh is too delicate.

For a crusted seared ahi steak, put a layer of roasted black and white sesame seeds, or fresh cracked pepper, on a plate, and press the steak down into the mix, covering both sides. Then heat olive oil in a skillet until it's just started smoking. Slap the steaks in and cook about 1 minute each side (for about a 3/4 inch slice) and serve. It should be rare. I particularly enjoy ahi served with wasabi mashed potatoes opposed to rice--simply some homemade mashed spuds with some wasabi powder blended in to taste.