Using a meat mallet (meat tenderizer), pound out the veal slices. Depending upon the size of the veal slices, you may need to add two pieces together. This is done by pounding out each piece, then seaming them together by overlapping the pieces and pounding them out a little more. Add the all-purpose flour, salt, and black pepper to a shallow bowl and whisk to combine.
Add two eggs and ¼ cup of milk or water to another bowl and whisk until well combined. This is the egg wash.
Add the panko bread crumbs, garlic powder, onion powder, and black pepper to another bowl and mix until well combined.
Dredge the veal in the flour mixture, completely coating the pounded cutlet.
Dip the floured cutlet into the egg mixture to completely coat the veal.
Add the egg-dipped veal to the breadcrumb mixture to coat the entire piece of veal.
Repeat the process with each piece of veal. Place small sheets of parchment paper or wax paper in between each breaded schnitzel to keep them from sticking together.
Add ½ cup of vegetable oil to a large skillet (or large frying pan), then place it over medium-high heat.
Carefully place breaded veal cutlet into the hot oil and saute until golden brown and crispy (about 2 minutes per side).
Remove the wiener schnitzel from the pan and place them on a wire rack or paper towels for one minute to drain the excess oil.
Serve Wiener Schnitzel with lemon slices, German potato salad, tossed salad, cucumber salad, spatezel or french fries.