I threw this together the morning of a cooking contest when my previous plan didn't work out. It turned out great: firm but not crunchy, a little salty and a little sweet but not overpowering. The sauce was just right. Even my 1-year-old ate some! I used ponzu sauce, which is a citrus-flavored soy sauce. I buy it at my local Asian grocery and use it often. Serve hot or cold, over brown rice or by itself. Splash on more ponzu sauce or seasoned vinegar as desired.