Combine the garlic, sea salt, dried oregano, cumin, chipotle chilie pepper, and cinnamon.
Place sliced onions in slow cooker.
Rub the mix all over the pork and place on top of onions.
Add the bay leaf and chicken stock. Cook on low for 8 hours.
Remove the bay leaf, bone and fat (it will literally fall off). Shred with two forks and combine in juices.