This is my second version of ponzu sauce that is vegetarian and closer to the bottled ponzu sauce. Whereas the first version of my ponzu sauce is based on katsuobushi - dried bonito flakes, this one is based on kombu - seaweed/kelp. You can find kombu bagged in dry form in Japanese or Korean markets (or some Asian markets). The first Ponzu Sauce is mellow with a nice aroma and taste of bonito and very little vinegar. This version is sharper in taste and more defined without any bonito taste or aroma. Although ponzu sauce is one of the sauces for shabu shabu, it is used as a dipping sauce for many Japanese hot pots known as nabemono. I use Meyer lemons for this version since I have no access for yuzu citrus yet. You can use any combination lemons, limes or some orange. Use 10 x 15 cm kombu cut in 3 pieces. The leftover kombu after soaking in the sauce can be used to line miso paste. It provides wonderful taste to miso. Note to those who never tried ponzu: This sauce is very versatile and you can use it top any steamed veggies, fish, meat, or tofu. You can also add a bit of oil to make into a traditional Japanese style salad dressing but go easy on oil!