Soya salad was a type of food, a salad made including Earth soybeans.
History and specifics[]
T'Vau, a Starfleet officer aboard the Federation starship USS Jefferson Randolph Smith in the 2260s decade, was known to request soya salad with kelp, and topped with oil and vinegar, for breakfast. Fellow officer Tatyana Trofimov was surprised by this, given the mess the dish inevitably made of the Vulcan's uniform. (TOS - Worlds Apart novel: How Much for Just the Planet?)