Kitchen (Treacherous Mansion)
From the Super Mario Wiki
The Kitchen is a room in Treacherous Mansion in Luigi's Mansion: Dark Moon. Accessed via a door in Grand West and located next to the Inner Courtyard, the room is a fairly traditional kitchen with three cupboards, a stove/oven, a fridge and a sink. There's also some pots and pans hanging from a rack near the ceiling.
This room has different ghosts and enemies in it depending on the mission.
During Double Trouble, the Kitchen is an optional room Luigi can explore while searching the mansion. In this mission, a Flytrap can be found behind the center most cupboard door; defeating it by firing the nearby cooked chicken into its mouth gets Luigi 20 Bills (100G). The fridge to the right is also invisible at this point and can be made visible with the Dark-Light Device. Entering the fridge door leads to a Bonus Challenge.
During A Train to Catch, the Kitchen has no Bonus Challenge gateway or purpose. The Flytrap is also gone.