カツ丼 (katsudon) is a type of Japanese dish that consists of a rice bowl with a tonkatsu, deep-fried pork cutlet, set on top.
The most common recipe uses a flavoring sauce, onions and beaten eggs. However, there are other variations, including one well-known recipe which uses Worcestershire sauce and shredded cabbage. To differentiate the two, the former is sometimes called "Tamago-toji [bound-together-with-egg] katsudon," whereas the latter is called "Sauce Katsudon."
On old Japanese crime/detective shows, the image of a detective working on investigating a suspect at the police station while eating katsudon is familiar to many.
The typical heart-of-gold type detective would think, "if this guy goes to the slammer, he'd never be able to eat anything as good as this again," and then use his own coin to order a katsudon delivered straight to the suspect's house. Then the suspect would be moved so much as to turn himself in and confess to the crime, tears streaming down his face. And so goes the cliche. For these stories, there is an explanation that katsudon was the most expensive food that one could get on a police officer's salary.
This fanciful description is nowadays only seen as either a worn-out stereotype or the butt of a joke or parody, but Japanese people have come up with the joking expression, "let someone eat katsudon," which carries the same meaning as "read someone their Miranda rights." (see post #1184509)
