Sapa[a] is a small Vietnamese restaurant near Mariahilferstrasse and Neubaugasse whose name comes from the village Sa Pa[b] (alternate spelling being "Sapa"). I went here on a whim, tried their PhoXao and was instantly hooked.
George and Phuong keep things running smoothly during the lunch rush.
Sapa after the murderous lunch rush (success has its price).
Dishes to try are the PhoXao (delicious noodles with chicken, beef or shrimp), the Cari (a potato, carrot and chicken "soup" served with rice - this one is by far my favorite) and BoBun. You can also get Pho here, but you have to be able to season it yourself - the soup itself is very much a blank slate. Be careful with the chilis when eating Pho, as the broth may end up eye-wateringly spicy before you notice it due to the time it takes for the little red things to release their dragon fire into the liquid, and because you won't feel it when eating the beef, noodles or meatballs.