17 hours ago, AlaMoi said:
there's only a few billion variations on "authentic" schnitzel. if you're in Austria, go one block down and you'll find a different "authentic" prep - the dish is so old not sure the 'original' can be documented there's a rumor the technique actually came from Italy, which has similar preps.
There is a classical preparation that's fairly well documented in the literature (e.g. Franz Maier-Bruck's Die österreichische Küche).
Regarding the theory that field marshall Radetzky brought back the Wiener Schnitzel from one of his campaigns in Italy, that has been pretty thoroughly debunked by Heinz Pohl (German only, sorry). It's a fairly newish invention, arising only in the late 19th century. The name Wiener Schnitzel is probably after the older Wiener Backhendl (Viennese fried chicken) with which it shares the breading technique.
Traditional side dishes for the Wiener Schnitzel are either cucumber or potato salad, although buttered potatoes with parsley are also sort-of OK. A lemon wedge is mandatory, fried parsley an optional garnish. Outside of Vienna, especially the farther west you go, you will be served Preiselbeermarmelade (a fruit akin to cranberries) and maybe even rice. While these may be minor heresies, you will never, ever be served any kind of sauce with your Wiener Schnitzel in Austria.