There are various ideas about what a proper Langos should be. But in Vienna they’re made from a potato dough, which is deep-fried and then coated in garlic paste. This is not as bad as it sounds (close though).
The result is a large, flat, round, crispy snack which can be quite warming and filling on a cold winter’s night.
The quality of the Langos depends on the quality of the oil used. All too often, street vendors fry their langos in oil that’s been reused and reused and reused…
The Langos has its origins in Hungary, where the name appears to apply to both a bread and potato version, but one generally thicker than the Vienna equivalent, and with more toppings (particularly cheese and sour cream).