Tonkatsu (豚カツ, とんかつ, or トンカツ, pork cutlet), invented in the late 19th century, is a popular dish in Japan. It consists of a breaded (breadcrums/panko), pork cutlet one to two centimeters thick first deep-fried whole then sliced into bite-sized pieces, generally served with shredded cabbage and/or miso soup. Either a pork fillet (ヒレ, hire) or pork loin (ロース, rōsu) cut may be used; the meat is usually salted, peppered and dipped in a mixture of flour, beaten egg and panko (Japanese breadcrumbs) before being deep fried.

Hire Katsu or high quality pork fillet served and cut into one bite size.

It was originally considered a type of yōshoku/洋食—Japanese versions of European schnitzel invented in the late 1800s and early 1900s—and was called katsu-retto (“cutlet”) or simply katsu. Early katsu-retsu was usually beef; the pork version, similar to today’s tonkatsu, is said to have been first served in 1890 in a western food restaurant in Ginza, Tokyo. The term “tonkatsu” (“pork katsu”) was coined in the 1930s.

In Korea, this dish is known as donkkaseu (돈까스), a simple transliteration of the Japanese word to Korean.

“Katsu sando/Tonkatsu Sandwich” as served in Okinawa

Variations
Tonkatsu has Japanized over the years more so than other yōshoku and is today usually served with rice, miso soup and tsukemono/pickles in the style of washoku/和食 (traditional Japanese food) and eaten with chopsticks. Recently, some establishments have taken to serving tonkatsu with the more traditional Japanese grated daikon and ponzu instead of tonkatsu sauce.

Katsudon

Tonkatsu is also popular as a sandwich filling (katsu sando) or served on Japanese curry (katsu karē). It is sometimes served with egg on a big bowl of rice as katsudon—an informal one-bowl lunchtime dish.

Regardless of presentation, tonkatsu is most commonly eaten with a type of thick Japanese Worcestershire sauce that uses pureed apples as a principal ingredient and is called tonkatsu sauce (tonkatsu sōsu) (トンカツソース), often simply known as sōsu (“sauce”), and often with a bit of spicy yellow karashi (Japanese mustard) and perhaps a slice of lemon. Some people like to use soy sauce instead. In Nagoya and surrounding areas, miso katsu—tonkatsu eaten with a miso-based sauce—is a specialty.

Variations on tonkatsu may be made by sandwiching an ingredient like cheese or shiso leaf between the meat, and then breading and frying. For the calorie conscious, konnyaku is sometimes sandwiched between the meat. And in Waseda, Tokyo, a restaurant serves a tonkatsu with a bar of chocolate sandwiched inside, sometimes compared to a Western creation: the deep-fried Mars Bar.

There are several variations to tonkatsu that use alternatives to pork:

Chicken katsu (チキンカツ) is a similar dish, using chicken instead of pork. This variant often appears in Hawaiian plate lunches.
Menchi katsu is a minced meat patty, breaded and deep fried.
Hamu katsu (ハムカツ “ham katsu”), a similar dish made from ham, is usually considered a budget alternative to tonkatsu.
Gyū katsu (牛カツ “beef katsu”), also known as bīfu katsu, is popular in the Kansai region around Osaka and Kobe.
Saengseonkkaseu (생선까스 “fish katsu”) is a Korean fish-cutlet modelled on the Japanese fry[citation needed].
Prices for a tonkatsu vary from 198 yen for a pre-cooked tonkatsu from a supermarket to over 5,000 yen in an expensive restaurant. The finest tonkatsu is said[citation needed] to be made from kurobuta (black pig) from Kagoshima Prefecture in southern Japan