They're always called "doubles," never in the singular. They're deep-fried and hearty, yet totally vegan. They retail for less than a fast-food soda. And they're the best Caribbean sandwich you've never heard of.
Doubles are a staple in the island nation of Trinidad and Tobago, a street food snack often eaten for breakfast. Like so many foods in Trinidad, where a substantial chunk of the population is of Indian descent, doubles have clear Indian roots. The filling is a spiced chickpea curry called channa, kicked up with a hot pepper sauce, pickled green mango, and a tart tamarind sauce. All that is sandwiched in hot, fried flatbread, and then rolled up in wax paper, because these little beasts are as sloppy as they come. (They're generally served as takeout street food, although eating them out of hand is a mean feat indeed. Get extra napkins.)
The best part? Most doubles will only set you back a buck or two, max—so a breakfast's worth of fried bread and chickpea sandwiches will ring in at under $5.