Tripe cooked in a rich mole sauce combines two Mexican culinary traditions into one dish. This high protein, carnivore-friendly meal is a family favorite with deep, complex flavors.
Rinse beef tripe thoroughly under cold water, then cut into bite-sized pieces; place in a large pot with the white onion and cover with water.
Bring to a boil over medium-high heat, then reduce to a gentle simmer; skim impurities from the surface and cook uncovered for 2 hours until the tripe is tender.
Meanwhile, toast ancho and guajillo chiles in a dry skillet over medium heat for 1–2 minutes per side, until fragrant but not burnt; remove seeds and stems, soak chiles in warm water for 15 minutes.
In the same skillet, toast torn corn tortillas, raw peanuts, and sesame seeds over medium-low heat until golden and aromatic, about 4 minutes, then set aside.
Blend soaked chiles, toasted tortilla, peanuts, sesame, garlic cloves, cinnamon, whole cloves, and chicken broth until very smooth.
Heat lard in a large saucepan over medium heat; strain the mole sauce into the pan and cook, stirring frequently, for 10 minutes until thickened.
Add Mexican chocolate, sea salt, and black pepper to the sauce; simmer, stirring, until the chocolate melts and sauce is deeply colored.
Drain the cooked tripe, reserving 1 cup of tripe cooking liquid; add tripe and reserved liquid to the mole sauce, stir well, and simmer on low for another 45 minutes to marry flavors.
Taste and adjust seasoning as needed. Serve hot, garnished with extra sesame seeds if desired.