The expression is often found in connection with the southern style of cooking (Cajun Kitchen), especially found in Louisiana.
Mid of the 17th century many immigrants from western France settled in Acadia, Canada, which is today’s Nova Scotia. They certainly brought their customs and their kitchen with them.
When France had to give up the land due to England’s superiority people often moved to the Louisiana area which was still French territory at that time.
Due to the diverse ethnic backgrounds of the people in this region languages mixed up over the time. The pronunciation of ‘Acadians’ led eventually to ‘Cajuns’. Over the time the kitchen of the Acadians (Cajuns) got influenced by Creole recipes and spices and the style of cooking that in now known as ‘Cajun kitchen’ evolved.