Selling Out - S1-E9
Frasier: Roger, at Cornell University they have an incredible piece of scientific equipment known as the Tunneling Electron Microscope. Now, this microscope is so powerful that by firing electrons you can actually see images of the atom, the infinitesimally minute building blocks of our universe. Roger, if I were using that microscope right now, I still wouldn't be able to locate my interest in your problem.
Answer: In the last episode, they explained that Tossed Salad and Scrambled Eggs is a metaphor for the mixed-up people to whom Frasier dispenses his radio psychiatric advice.