Preheat the oven to 250°F

In a small dish, mix the salt, pepper, chipotle, cumin, and oregano together. Rub the spice mixture over the surface of the pork and set aside.

Add the onion, jalapeno pepper, canned chipotle peppers, garlic, and cilantro to the bottom of a Dutch oven or large covered ovenproof casserole. Add the seasoned pork and pour the beef broth around the pork. Bring to a boil over medium-high heat.

Remove the pot from the stove, cover it with a lid and transfer it to the middle rack of the oven. Cook for 2-1/2 to 3 hours or until the meat falls apart.

Remove the pot from the oven and transfer the pork to a large platter and allow it to cool slightly. Discard the cooking vegetables, strain the cooking liquid and refrigerate it.

When the meat is cold, and the fat rises to the top, remove the fat, reserving enough to crisp up the bottom of the pork and discarding the rest. Reserve the remaining liquid, if any, for another use. It may also be frozen. Using two forks, shred the meat, discarding the fat, bones, and grizzle parts.

To make a crispy crust on the bottom: Set a large heavy-bottomed skillet or Dutch oven (cast iron skillet is my choice) over moderate heat and add a tablespoon or two of the reserved fat. When it has melted, add the pork and brown it so that it gets a nice crust on the bottom. It may be necessary to do this in batches if your skillet isn’t large enough.