Most government leaders have unofficial non-elected advisers outside their legitimate cabinet and these people have been labelled a “kitchen cabinet.”
The expression was coined in 1832 when Andrew Jackson (1767-1845) was president of the United States.
He used to hold frequent unofficial private meetings with three close friends, and in order to avoid scrutiny or criticism, they entered through the back door of the White House and then through the kitchen.
From that time on the press referred to the president’s inner circle as the “kitchen cabinet.”