Olla podrida is found back in an 18th century Dutch cookbook as Olypodrigo. A heritage from the Spanish rule. It is in origin a Spanish 16th century festive dish that figures in my 1761 facsimile book. (the Spanish were out in 1648)

To make a sumptuous Olipodrigo
Take a clean Capon, Lamb, Veal, Beef, cook it until almost done, then take Sausages, Pigs' feet, Sheep's feet, and a krap [piece of porc with bone in], two Marrow-bones, some little Veal meatballs, cook those together until almost done, Endive cooked for a while, and add Sweetbreads with Ram balls, let it stew together with the Endive in your pot; add whole Pepper and Mace and pieces of Nutmeg, then place the Sheep's and Pig's feet on the bottom and layer the other meat proportionately,(ha!) let it stew together for half or three fourth of an hour, then pour off the broth, in the same [broth] add 4 or 5 Egg yolks which have been beaten with some Verjuice, do add some Butter and let it come to a boil together; pour this over everything after you have put it [the meats] in the dish. Also take Chestnuts, Asparagus, or Artichokes, according to the time of the Year, add those [after they are done] to the dish, sprinkle the rim or the entire dish [with] two hard boiled Egg yolks, crushed Rusk, and Parsley which has been cut with the others [egg yolks and the rusk]. Is good.
Verjuice: juice from unripe grapes or apples.

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..."