It is said that this Scottish soup derives from the times when cockfights were popular. The cock who lost, was used for stock along with leeks. Prunes have been added at a later date.
A recipe from the reign of Queen Elizabeth I
found on cookite2bn.org
Oranges were not used very often in this period but, from recipes such as this, we know they were sometimes available. It was said they were made popular by Catherine of Aragon, King Henry VIII’s first wife, who was from Spain. Oranges were bitter and so some lemon juice should be added to make the dish taste sharp or tart.
This is a development from earlier medieval sauces which used wine vinegars or verjuice (made from crab apples) to make sauces for fish or game.
Many medieval dishes serve roasted or boiled meat with an accompanying sauce. Sauces are often complex and some are spiced and fruited. Mint sauce, apple sauce and rowan jelly are still sometimes served with meat today.