Schnitzel is a specialty of German speaking countries, and according to legend, an inventive cook either in the 15th or 16th century had the idea of pounding a piece of meat thin, breading, and frying it in a pan with plenty of oil.
Although the origin of schnitzel cannot be pinpointed exactly, the birthplace of Wiener Schnitzel is not disputed. By law, Wiener Schnitzel must be made using veal (either tenderloin, loin, or slice of round from the hind leg), and breaded with mie de pain (not to be confused with miette de pain), not bread crumbs. Mie de pain uses only the white part of the dried white bread. The final product has a much finer taste and texture.
There are many variations of schnitzel. First of all, in Germany schnitzel has come to mean a thin, pounded piece of mostly pork (loin or tenderloin), then there is Pariser-, Zwiebel-, Rahm-Zigeuner-, Paprika-, and Jagerschnitzel.
French chefs know when they see a culinary invention worth copying, but they call it escalope de veau Viennoise, never schnitzel.
The first and most important thing for success is to buy lean, naturally raised meat (veal or pork) from a caring butcher, then proceed as follows ; pound the meat (6 mm. or ¼”) thin with a mallet, season, dip in flour (dust of excess flour), then into egg wash, coat with bread crumbs (some use double breading), and shallow fry in olive oil, or sunflower oil, or peanut oil, or preferably in duck fat or lard, and never deep-fry as some careless professionals do out of convenience.
If you fry fro too long, the breadcrumbs burn. To avoid this, fry the meat until it is golden brown, and finish cooking it in a hot oven.
Breading actually steams the meat inside and gives it a special texture and flavour in contrast to the crust which is crunchy and delicious.
Wiener schnitzel is served with a wedge of lemon and a salad with vinaigrette.