The large heads of animals like hogs, pigs, cows, sheep, once cleaned or any internal organs, are boiled in a large tub/kettle (usually outdoors over an open fire) for approx 24 hours. The skull is removed and the contents (slivers of meat, bone marrow, etc) are used in making many different foods. In Mexico, they often use this meat for making tamales. You can also use it to make Mexican Menudo just use it in place of the calf's foot.
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