Tsuyu

This sauce, which doubles as a soup base and a seasoning, is diluted for use as a broth for hot soba and udon or as a dipping sauce for soba and tempura. Most versions of tsuyu contain dashi, sake, soy sauce, and sometimes mirin or sugar. Tentsuyu, the classic dipping sauce for tempura, is a concentrated version of tsuyu, probably to balance the relatively strong flavor of the fried food. You can use a purchased sauce, diluting it as indicated on the bottle, if you don’t want to make the homemade sauce that I have included with the tempura recipe. I have also included a homemade tsuyu sauce, milder than the tempura version, for dipping cold soba. A mild tsuyu is also recommended for Agedashi Dofu, but since you need only a small amount, a diluted bottled product is easiest.