Almost every piece of meat on a cow’s head is edible. In fact, these succulent bits are the foundation of the popular borderland food barbacoa de cabeza, or cow’s head barbecue. Nothing makes a more ideal platform for exploring the wonders that await inside a cow’s head than the taco. Along with the likes of more popular head-based fillings, such as chewy lengua (tongue), there’s the lesser-known, but no less alluring, taco de ojo, or eye taco.

In the Lower Rio Grande Valley, barbacoa de cabeza’s home, cow heads were traditionally buried in pozos or wells, where a barrier of maguey leaves protected them from the coals as they steamed in their own juices. Today, cooks steam the heads in large pots over a butane burner. When it’s time to remove the eyes from the head, they reach into the eye socket and extract the bulbous organ. After separating and discarding the sinewy nerve, they’ll chop the gelatinous orb into juicy cubes.

Street vendors deposit these springy chunks onto warm corn tortillas, where the well-dressed taco de ojo gets decked in lime, pico de gallo, red chile sauce, and fresh, sliced avocado.