"One doubles," a lady in line was ordering at the counter of Ali's Roti Shop. Is this some sort of code language that only Caribbeans know? How can you have just one doubles? It turns out that doubles is the essential snack food of Trinidad, and doubles is/are delicious. It starts with a small biscuit-sized disk of fried bread that is slathered with a thick chickpea curry and then topped with another round of bread. This finger sandwich of sorts may sound like a vegetarian dainty, but it packs a wallop. Especially if you ask for the hot sauce, and you should. The turmeric-colored bread is as soft and comforting as a pillow, and at first you might think you're taking a bite out of the Pillsbury dough boy. Then you hit the warming, earthy chickpea mixture, spiked with tamarind, cilantro, and cumin.

The combination sounds Indian, and it is, by a circuitous route. Doubles are a descendant of chaat, the tidbits sold at roadside stands in India. When Indians came to the islands of Trinidad and Tobago, they brought with them their culinary traditions and created doubles, a delicious vehicle for cheap but nutritious ingredients. Now you can find them throughout the outer boroughs: Ali's has another branch at Utica Avenue between Carroll and President. And there are other Ali's (unaffiliated with this one) in the North Bronx at 4220 White Plains Road and in Bed-Stuy at 1267 Fulton St. (Will Ali's Roti one day supplant Ray's Pizza in the category of invasive franchises?) But the Ali's on Flatbush has the advantage of being located close to the Prospect Park stop on the Q train. So next time you're headed to the park, swing by for some inspired picnic fare. At just a dollar each, you can afford to get two, or even four, doubles.