Tacos de sesos

Pasos

1. Submerge the beef brains in a large bowl of ice-cold water mixed with the distilled white vinegar. Chill and soak for 15 minutes to purge any blood, then gently peel away the thin outer membrane and surface blood vessels under a gentle stream of cold running water, taking care not to break the lobes.
2. Place the cleaned brains in a saucepan and cover generously with cold water. Add part of the white onion, part of the crushed garlic cloves, the dried bay leaves, part of the fresh epazote sprigs, and fine sea salt. Set over medium heat to bring the water to about 185 °F (85 °C) just as it begins to tremble, then immediately reduce the heat to low to maintain a bare simmer for 12 minutes, until the brains turn completely opaque and feel set yet tender to the touch.
3. Gently lift the brains from the broth using a slotted spoon and transfer to a clean cutting board. Let rest and cool slightly for 10 minutes to firm up for clean slicing, then cut into uniform 1-inch (2 to 3 cm) pieces.
4. Melt the traditional lard in a cast-iron skillet over medium-high heat at about 340 °F (170 °C). Finely chop the remaining garlic and part of the remaining white onion, thinly slice the fresh serrano pepper into rounds, and add them all to the hot fat. Cook for 3 minutes, stirring, until the onion turns translucent and lightly browns around the edges.
5. Add the poached brain pieces and the remaining chopped fresh epazote sprigs to the hot pan at about 355 °F (180 °C). Sear over high heat for 5 minutes, turning gently with a spatula, until a crisp golden crust forms on the outside while the center stays silky. Season with fine sea salt.
6. Heat a dry skillet or comal over high heat to 400 °F (200 °C). Warm the nixtamalized white corn tortillas for 30 seconds on the first side and 20 seconds on the second, until pliable, slightly puffed with air pockets, and marked with light brown spots.
7. Immediately fill each warm tortilla with the crispy, tender pieces of brain. Top with the remaining finely chopped raw white onion and fresh cilantro. Spoon over the Mexican tomatillo salsa verde and serve immediately with lime wedges for squeezing over the tacos.