That distinction is reserved for the patacón Maracucho, a Venezuelan specialty that's finding fans in New York. At this Colombian restaurant the patacón de guacamole ($8.50) is a broad platform of twice-fried, flattened plantain, also topped with queso blanco and chimichurri sauce. It's eaten with knife and fork, but if you insist, "open-faced sandwich" doesn't stretch the point too far.
Also: a chicken-and-potato empanada in close-up (it's about half the size of the patacón). This empanada ($3) had an unusually supple crust; excellent, even before a dose of that aji pepper sauce.
Bogota Latin Bistro
141 Fifth Ave., Park Slope, Brooklyn