From the Houston Press Eating Our Words blog:

This recipe originally appeared during the rodeo barbecue cook-off. It’s complicated, but the results are spectacular.

Borrego actually means mutton in Spanish, but for some reason, Anglos are more comfortable translating it to “lamb.” Which is odd when you think about it, since Anglos are usually squeamish about eating veal, suckling pig, tiny cabritos and other baby animals.

Mutton used to be a traditional meat in Texas barbecue and is still found at a few African-American barbecue joints such as Ruthie’s in Navasota and Sam’s in Austin. So call this “Mexican mutton barbecue” if you like.The smoky-flavored, falling-off-the-bone tender meat this recipe yields is even tastier than the the stewed goat dish called birria.

Mexican barbacoa is still made in a smoker by a few Tejano barbecue enthusiasts, but commercial pit barbacoa is all but extinct in Texas. Vera’s in Brownsville is one of the last restaurants in the state to use a real pit to make barbacoa. In the old days, Mexican ranch hands used to wrap cow heads up in canvas or maguey leaves and bury them in the coals. (In the movie Giant, Elizabeth Taylor faints when they unwrap the package and show her the head.) But health departments frown on such traditional barbacoa these days.
read more The Tex-Mex Grill: Barbacoa de Borrego »