Gabe’s Steamy Diner is a one time location that appears in R64: Mario The Waiter.
As a result of his kart getting destroyed, Luigi decided to work there as a waiter to buy a new one. However, when Mario discovered the place, he decided to work there. Being “hired”, the red plumber decided to watch cooking videos, which didn’t aid him in his cooking. Throughout his time in the diner, he ended up displeasing many customers, which included leaving Big Smoke continuing to rant about his order, and a cake that harmed Toad and Toadette. Mario also ended up displeasing his manager right in front of him, the latter catching the former disrespecting Frankie and not serving SMG4. As a result, Gabe banished Mario and Luigi to the dimension of his face, Big Smoke being there to annoy the duo.