dirty kitchen

Short definition from Wiktionary

Noun

1. 1
   A kitchen where everyday cooking is done by household staff, as distinct from a kitchen that is purely for show or for special use by the owner of the house.
2. 2
   A kitchen, sometimes auxiliary or situated outside the house, used primarily for preparing messy and smelly dishes or cooking with firewood or charcoal. It is also used for cooking for a large group of people.