Fuente Alemana is one of the oldest snack bars in Santiago, operating on the Alameda since the 1950s. It is a quick-service counter restaurant focused on one thing: the Completo — the Chilean hot dog. The Chilean version is loaded with avocado, tomato, sauerkraut, and mayonnaise, and Fuente Alemana's are considered among the best in the city. The Italiano (avocado, tomato, mayonnaise — the colours of the Italian flag) is the classic order.
It is not a sophisticated dining experience, but it is an entirely authentic one: office workers, students, and construction workers all eat here together. Very cheap and very fast. A good introduction to Chile's street food culture without having to find a street cart.