The taco filling made from a thin cut of beef between the belly and the leg is suadero.
In Mexican cuisine, suadero refers to a thin, smooth-textured cut from the area between a cow’s belly and leg. Unlike cuts prized for visible muscle grain, suadero is valued for its relatively uniform texture. Taqueros commonly cook it slowly in fat or fry it until tender before chopping it for tacos.
Suadero is especially associated with Mexico City’s street-taco stalls, where it is served on corn tortillas with onion, cilantro, salsa, and lime. The meat can also appear in tortas and gorditas. A common mix-up is treating suadero as a cooking style rather than the name of the cut itself.
The term also varies internationally: related cuts are called matambre in Argentina, sobrebarriga in Colombia, and rose meat in the United States. Those names are regional equivalents, not the usual Mexican taco name.