The Kitchen is a Dome in Super Mario Galaxy. It is the third accessible Dome, and must be unlocked by recovering the Grand Star from Bowser's Star Reactor. The main boss of the Kitchen is Bowser Jr.
The Kitchen has brick walls with an eternally-smoking chimney on top. Inside is a wooden floor with a raised star-shaped platform in the middle. The Kitchen also has a sink and a fireplace. There is also a 1-Up Mushroom behind the tower that the Kitchen is situated upon. As with all Domes, the Kitchen has a Pull Star in the middle which is used to access the Dome's Galaxies.
When the black hole of Bowser's Galaxy Reactor was formed, Princess Peach's Castle was forcefully pushed through the nothingness and collided with the Comet Observatory, sending the kitchen off into space without the Observatory.