Suadero is a cut of beef that lies between the lower flank and sirloin primal sections of a cow that is often used in Mexican cooking. Used as a taco delicacy in and around Mexico City, this meat is considered lean and even a little chewy. Due to its lack of fat, the best way to cook it is in low heat for a long time, with flavorful steam or smoke to keep the meat moist and as tender as possible.
Many primal charts for cows do not show the suadero cut of meat. Instead, many merely include it as part of either the bottom of the sirloin, or round/rump sections, or at the tail end of the flank section, on the underside of the cow. At the nexus of these three sections lies the suadero, which is often differentiated by Mexican butchers and chefs, since the cut is so popular as a taco filling.
The suadero is found on top of the cow's udders in a largely underworked section below the belly. The fact that this part of the cow is not particularly active makes a meat similar to hanger steak, but with a little more gristle and chewiness. Some cooks lump other similar cuts into this category when preparing tacos, such as brisket, skirt or flank cuts.
To get the right flavor into the beef, cooks often dry rub it or marinade it with seasonings like chile, garlic, onion, cilantro and salt. The meat is then cooked with a slow-cooking process like braising or smoking — both of which are intended to preserve moisture. Then, upon service, cooks will often slice and toss the cooked meat on a hot grill to quickly sear it before placement in hard or soft tacos with customary accompaniments like lettuce, onion, chopped cilantro, lime juice, and green or red salsa.
Taquerias in Mexico and abroad often offer a range of taco fillings. A few of the more traditional preparations from the cow are called carne asada, the spicy barbacoa, simple ground beef, and even meat from the head, called cabeza. Some forgo beef all together and favor pork cuts that most frequently make their way into tacos, including the tender carnitas and the gyro-like al pastor.