Unagi Sauce NIHON SHOKKEN Ungai (eel) sauce is rarely made at home. An eel bone broth, soy sauce, rice wine and sugar is first made as the base sauce, and it is continuously flavored by dipping grilled eel with the sauce, which is part of the grilled eel preparation process. Some eel restaurants have been using the same sauce mixture for over a hundred years and keep adding the base sauce every day.
