Roshi on Yoshi is the name of two completely different, yet utterly horrible things in the Tiradesverse.
In Episode 32, James and Damien decide that the Roshi on Yoshi is scrambled eggs with dinosaur bits. In Episode 35, James and Damien conclude that Spam is made from dinosaur. Fans have used the associative property to conclude that scrambled eggs and SPAM combine to make the Roshi on Yoshi.
It may also be a really awful, banned sexual maneuver.