It's a song all about eating salad, but just wait for the finish!
The Ross Sisters were a trio of sisters, all singing dancers consisting of Aggie Ross, Elmira Ross, and Maggie Ross, (whose real names were Veda Victoria, Dixie Jewel and Betsy Ann Ross).
They performed as a 3-part harmony trio, in which they also danced and did acrobatics and contortionism. Their public attention peaked during the 1940s, during which they were featured prominently in the film Broadway Rhythm. A shortened version of this same clip also appears in the compilation film "That's Entertainment! III" (1994).