For the beef: Place the cubed beef heart in a mixing bowl. Add all the ingredients except the wine and mix. Add the wine and mix. Cover and refrigerate for 24 hours.

Prepare a fire of pinon, mesquite, or charcoal. Drain the beef hearts, reserving the marinade. Thread the cubes onto skewers and season with salt.

When the coals reach a dusty red glow, grill the hearts, turning often and basting with the remaining marinade. Beef hearts are best served rare with salsa.

Salsa Rena: Remove the stems and seeds from the chiles and soak in a bowl of warm water for 20 minutes. Drain the chiles. Process the chiles in a food processor, turning the machine on and off until they begin to puree. Add the oregano and a generous amount of salt. Turn the processor on and gradually add the oil. For a very hot sauce, add chile seeds to suit your taste.

Serve with grilled beef hearts or with tequila as a chaser.