When Agatha enters Castle Heterodyne for the first time as a supposed prisoner, she is taken by Sanaa to work with Moloch in Venthraxus Heterodyne's personal kitchen, which is used by the current batch of inmates for their food preparation, as they haven't found the main kitchen yet. The room is under the control of one of the Castle's fractured subsystems, which it thinks of itself as simply Castle Heterodyne. It is thus able to have an a floating array of kitchen utensils menace anyone currently inside it.
It was originally the personal kitchen of Venthraxus Heterodyne's unnamed favorite chef (but "the Unnamed Chef's personal kitchen" is a terrible article name). This chef went crazy, believing himself to be a reincarnated Borgia, probably Lucrezia Borgia, and began poisoning everything he made. In true Heterodyne style, Venthraxus found this funny, and had a separate kitchen made for him. The chef lived there quite happily until he accidentally ate his own cooking. Venthraxus probably found that hilarious. All the background on the kitchen was provided by the kitchen AI itself, which has a reputation for talking... but atypically, not for killing anyone.
The greatest priorities for the kitchen would be the food preparations and cooking conducted within it--so much so it will abort attacks for the sake of preserving a souffle. It was also the very first part of Castle Heterodyne to sample Agatha's blood which, you will likely notice, happens at the far end of the first reference link in this article. Unfortunately, it almost certainly does not possess the facilities needed to actually test that sample..
Semi-Canonical Information Edit
The print novel Agatha H. and the Voice of the Castle expands on this scene, offering a couple of new details. One is giving the chef a name, Luigi del Basteri, and noting that the particular Borgia he thought he was varied from day to day. Sanaa also theorizes that the kitchen, in addition to enjoying mentally torturing people rather than outright killing them, has also accepted that the prisoners are trying to repair it, and have to get food somehow.