Put the pork in a crock pot and add salt, pepper, oregano, cumin and chili powder to both sides of the meat.
Add the onion, garlic, serrano pepper, bay leaf and cinnamon stick on top.
Squeeze the oranges and lime on top and then cook on high for 4 hours or low for 6-8.
Shred the meat with two forks. Heat ghee in a skillet and fry the meat on one side until golden and crispy.
Reserve the juices in the crockpot and pour some on top of the meat. Squeeze lime juice on top and serve.