I don't know why this is a historical question.

Even back in the 18th century kitchens in larger households had professional cooks. They were trained through apprenticeships, so they could be women or men (compared to things like law which was exclusively male), but this requirement of being a "professional" very often skews towards men. Particularly in the 19th century when the middle class emerges and women working becomes less common and less desirable (i.e. if both spouses work they must be poor). These professional cooks are now mostly men and are hired into business locations. Or are able to open their own restaurants. Women are more likely to work in others homes as a cook, though technically still professionally hired. Though chef and cook were very similar, they were used to differentiate between cooking for the public and cooking for a home.