The Chip Butty is a building in the desert that is shaped like a chip butty sandwich. It is entered through the Gourd. The Mouse Puzzle has to be solved in order to unblock the passageway between Gourd and Chip Butty. Found in this room are two disks and the projector, which projects an upside-down picture of Willie Trombone if pushed into the electrical output on the floor (+ –).
The Chip butty article on Wikipedia mentions "the chip butty made appearance as a house in the PC game The Neverhood, introducing the dish to foreign gamers".