Rub salt on all sides of the pork; set aside.
In a dry skillet, over medium heat, add cumin, peppercorns, allspice, cloves and cinnamon stick; toast for a minute or two until you can smell the cumin and pepper.
Using a spice grinder, coffee grinder or mortar and pestel set, grind the toasted spices to a powder.
In the same skillet, toast the garlic cloves until they’re charred all over; add to a blender or food processor.
Add the chile powder, oregano, achiote paste and citrus juices; puree until smooth; set aside.
Place a trivet or a ring of scrunched up aluminum foil in the bottom of the crock pot.
Cut 2 pieces of kitchen twine or string twice the length of your pot; lay them across the pot in a (+) orientation (like gift wrapping a box).
Next, place two banana leaves in the crock pot, in a (+) orientation (again, like gift wrapping a box).
Pour some of the marinade on the top of the banana leaves; put the pork on top in the center of the crock pot.
Pour the remaining marinade over the entire pork and carefully fold the banana leaves up and across the pork (like wrapping paper).
Tie the kitchen twine together for a complete sealed package.
Set the entire pot in the refrigerator for 4 hours minimum or overnight.
Take pot from refrigerator and set on counter for 15 minutes.
Pour a 1/2 cup of water into the crock pot; cover with the lid.
Cook on low for 8 hours or until the meat is very tender and pulls easily with a fork.
While the meat is still warm, carefully transfer the parcel to a serving dish.
Use tongs or forks, shred the meat and spoon the cooking juices over meat.
Serve with warmed tortillas, beans, pickled onions, cilantro and limes.