Empanadas are a dish made in Spanish and Latin American regions, with many variations coming from all the different countries. They are made with dough and stuffed with all types of fillings, either savory or sweet.
At El Porteño in the Island Earth farmers market inside the Metreon, they make Argentine-style empanadas, which are the traditional half-circle style empanadas that are typically served at most restaurants. The empanadas are baked, not fried, and are stuffed with a number of different fillings.
The Jamon y Queso that I had was very tasty, and it was the first time I ever had prosciutto and cheese in an empanada! They have a very light and flaky crust, unlike the typical thick and dense shell normally used. The shell was my favorite part, as it was a little different from empanadas I've had before, in a good way. The flaky crust was buttery yet light, and did not overwhelm the filling.
At only $3 each, they are cheap enough to grab as a quick, light meal on the go, or grab a couple and make a meal out of it. There are different flavors, so try them all and decide which one(s) you like best. The Island Earth farmers market is open daily inside the Metreon building in downtown. El Porteño empanadas are also available at other farmers markets around the Bay Area or you can order them direct by the dozen, as well.
For more info: http://www.elportenosf.com, http://www.islandearthfarmersmarket.org
Also check out:
Fresh pupusas at Balompie Cafe in the Mission
$1 Ahi tuna tartare tacos at Andalu every Tuesday night
Buy one burrito, get one free at Taqueria Los Coyotes in the Mission