Don't confuse the different varieties. It must be soaked before cooking. I also keep sesame and carraway seeds around, too. It's the 8-pointed fruit of an evergreen native to China, and is essential to good Chinese and SE Asian cuisine. There are almost as many varieties of rice wine vinegar as there are rice wine.
Chinese vinegars tend to be darker in color and stronger tasting than the clear Japanese variety.
Keep some of both on hand. This is different from Japanese mustard and is a pungent green horseradish-like sea vegetable used most often with sushi. The hammered sides are great for holding vegetables in place so they don't become soggy if you use the wok for steaming with the wok cover on. TOP Yogurt - Use only the unflavored kind.