La Fortaleza, La Delicias, two food trucks, they park on Sundays just west of Present Restaurant, Rt. 50, Falls Church, VA (approximately 6680 Arlington Blvd., Falls Church, VA), Sunday, roughly 11-7.
This is the best and most authentic Bolivian food around. Get the sopa de mani (peanut soup), enrollado (make sure you taste the green leaf with it), chicarron (superb and super soft and juicy), and solterito, which mixes beef, white cheese, onion, tomato, Bolivian corn, and potato. They also have chairo, falso conejo, tilapia Bolivian style (sometimes), and many other authentic dishes. They don’t have real seating but it doesn’t matter, this is the place to go. A+ for atmosphere too, knowledge of Spanish helps.
photo credit: Mr. T in DC