In Don Quixote -- first published in 1605 -- Cervantes has the gluttonous Sancho Panza say these words:
"This plate that is steaming in front of me appears to me to be olla podrida, because of the diversity of ingredients that there are in some ollas podridas, I won't be able to stop running into some that is to me of taste and benefit..."
The dish appears to be substantially the same as the French oille (popular in the eighteenth century) and its English equivalent, the olio (not to be confused with the Italian word for oil). Though the specific meats and vegetables varied locally, all were thick stews with a rich diversity of ingredients.