Biergarten is great and the food is real authentic. (beside McCheese that is not know at Germany at all

)
Real Viennese Schnitzel HAS to be veal! Very slim slices put first in flour than in whistked eggs and at last in breadcrumb. Pan-fried afterwards.
Schnitzel can also be pork than it is called viennese style
Sauerbraten is beef marinated in vinegar and spices at least 12 hours and then roasted in the pot. When you have a "Rheinische Sauerbraten" there has to be Pumpernickel (some kind of very dark bread) and raisins in the sauce.
Its great with Spätzle and applesauce.
If you need some more explanations of the German food dont hesitate to ask.
Greets from Germany
Renate