BROOKLINE - A large cylinder of meat topped with half a pineapple turns slowly on a vertical spit at Anna’s Taqueria, while glowing heat from two burners sears the outside to a rusty brown. Manager Carlos Castellon, wielding an extremely sharp knife, cuts slivers of the glistening pork in a gentle shaving motion. He quickly cooks red onion on a griddle, adds the chunks of meat and lets them crisp slightly, then places the mixture on a corn tortilla with a few bits of pineapple. This is tacos al pastor, a Mexican specialty and a relative rarity in the Boston area.
Tacos al pastor, literally shepherd’s-style tacos, are similar to Middle Eastern shawarma, Greek gyros, and Turkish doner kebab. A popular street food, the snack in Mexico is sold at taco shops (taquerias), stalls, and carts. The dish traveled first to southern California, then to other restaurant kitchens with Mexican immigrants. Anna’s owner Michael Kamio says it was a former employee from Mexico who taught them how to make the spit-cooked pork. Today, Castellon, who is from El Salvador, and a few others, are in charge of preparing the meat.
What make tacos al pastor a novelty is both the cooking method and the flavor of the pork. Thin slices of marinated shoulder are threaded onto a vertical skewer - along with layers of slivered onion that permeate the meat as it cooks - forming a large stack that Kamio refers to as a ball (bola in Spanish), also known as a trompo (like a child’s spinning top).
“The outside [of the ball] is always cooking,’’ says Kamio. “We shave off pieces of meat and then the next layer gets cooked.’’ At Anna’s, each ball is made up of three to four pork butts and on a busy day, at each of their six restaurants, they might go through two or three balls.
It’s the overnight soak in a chili-based marinade that provides the distinctive spicy-smoky, earthy-sweet flavor. Marinade recipes are typically a well-guarded secret, as the one at Anna’s is, but Kamio and Castellon offer up some of the key ingredients, including ancho chilies, onion, cinnamon, garlic, and orange juice.
Two other area restaurants, Fort Point Channel’s Papagayo and Cambridge’s Ole Mexican Grill, serve authentically seasoned tacos al pastor, but neither operate a rotisserie. In both cases, the meat is grilled. At Papagayo, chef and co-owner Chris Damian says his restaurant uses pork tenderloin, a more tender cut than shoulder, which is marinated and grilled whole, then sliced for tacos.
Damian says he fell for the dish while traveling in Mexico and talked his way into a few restaurant kitchens to learn how to make the marinade. One of his chefs, a native of Guadalajara, Mexico, helped him refine the recipe. Ole’s co-owner Erwin Ramos also sampled tacos al pastor at street vendors throughout Mexico, occasionally noticing that some cooks add chopped, fried bacon to the pork to give it more smoky flavor. While he doesn’t use bacon, Ramos adds achiote seed (from the annatto tree) to the marinade, which is traditionally used to tint the meat a reddish color.
Also traditional is a half or whole (peeled) pineapple sitting on top of the ball or trompo. Anna’s Castellon explains that as the fruit warms, the juices baste the meat. It’s understandable how the two foods came to be paired, as piquant pork and sweet-tart pineapple are natural partners. Be careful how and when you use the fruit. An enzyme in pineapple, called bromelain, breaks down protein and acts as a tenderizer for tough meats. Too much of it can be disastrous. Fresh pineapple or fresh-squeezed pineapple juice in a marinade will turn meat to mush if left more than a few hours. (Cooked or canned pineapple doesn’t have the same effect.)
For taco lovers, tacos al pastor is a good way to get your hands around a small corn tortilla layered with smoky, hot, salty, and sweet tastes. No street vendor necessary.
Anna’s Taqueria, 1412 Beacon St., Brookline, 617-739-7300; 446 Harvard St., Brookline, 617-277-7111; 822 Somerville Ave., Cambridge, 617-661-8500; 236A Elm St., Somerville, 617-666-3900; more locations at www.annastaqueria.com Papagayo, 283 Summer St., Fort Point Channel, Boston, 617-423-1000, www.papagayoboston.com Ole Mexican Grill, 11 Springfield St., Inman Square, Cambridge, 617-492-4495, www.olerestaurantgroup.com