They call it "Pollo a la brasa," and it's cooked on spits rotating around like a carousel, about 30 chickens at a time. The smoke perfumes the air for blocks around (probably not so great for global warming; oh well). There are several such restaurants/chains in the DC area; the best is El Pollo Rico, in Wheaton (I heard the Arlington one closed). Servings are huge and cheap, the meals completely proletarian: your choices are a quarter chicken or a half, dark (pierna) or light (pecho); and three choices of sides (you get two) - steak fries, coleslaw, and not-so-great tortillas. They give you two sauces, one a fiery green one (too hot to be jalapeño) and a mayonnaise-y one.
Anyone else have Peruvian chicken in their area?