• Thin pieces (or pieces you can cut thin) of lean, tender meat, like veal cutlets, pork loin chops or chicken breast (it's gotta be veal for Weiner schnitzel)
• salt
• pepper
• flour
• egg (with maybe some mustard mixed in)
• breadcrumbs (I recommend panko that you process into a fine powder)
• oil (clarified butter or lard would be traditional, but a neutral frying oil would be fine)
• parsley for garnish (optional)
• lemon for garnish (not optional)

1. If your meat isn't already really thin, cut it thin, then cover it with plastic wrap and pound it with something smooth and heavy until it's as thin as you can get it without tearing it apart. Season with salt and pepper. Dust in the flour and knock off any excess. Dip in the beaten egg and knock off any excess. Coat in breadcrumbs, but be gentle — don't press the meat into the crumbs.
2. Heat half an inch (1 cm) of oil at most (and probably a little less) over medium-high heat. Dip the edge of the meat into the oil. If it doesn't sizzle, get the oil hotter. If it goes totally crazy, turn the heat down. Fry the cutlets on each side until brown, flipping frequently so that you can see if anything is burning. There should be enough fat in the pan to where the meat is floating, but not submerged. As soon as they look done on the outside, they'll almost certainly be done on the inside. Drain on a rack or paper towels. Top with optional parsley and mandatory fresh lemon juice at the table.

Pair with Cucumber Salad, See also Clarified Butter

source https://youtu.be/4eGNy2E7CVs