I grew up hearing many parables or tales from my dad - French or German - they seam to be common in the European arena and the Ox tail soup reminded me of a favorite - called "golden eyes".
According to my dad's story - a french king would visit his subjects incognito, dressed as a simple hunter, often.
The story goes that he first visited one of his nobles, who did not recognize him and asked to stay the night.
The Noble puts him up in the stables with dirty hay for a bed and watered down soup for supper.
The next night he asks to stay at a peasant's house - who also does not recognize him, but gives him his own bed to sleep and for dinner, a rich and hearty soup, full of "golden eyes" or the fat from meat.
The story continues that when the king returned to his place, he calls the Noble and the peasant before him and tells the noble that the peasant treated him far better. Then instructs the noble to give the peasant a gold coin for each golden eye that the peasant's soup had in punishment for being such a poor host to strangers. Of course, there is a similar parable in the new testament - saying be kind to strangers for they may be angels.