Heat oil in a large skillet over high heat.

Add the pork and sear on each side until browned (about 2 minutes per side). Transfer the pork to the slow cooker.

In a small bowl, stir together chicken broth, onions, garlic, chipotle and spices. Pour over the pork in the slow cooker.

Cook on low for 6-8 hours until the pork is completely tender and shreds easily with a fork.

When the pork is cooked, preheat the broiler to high heat and cover a baking sheet with aluminum foil.

Using a fork, shred the pork into bite-sized pieces, then use a slotted spoon to transfer it to the baking sheet, spreading it evenly in a single layer. Do not discard the remaining broth from the slow cooker.

Place the baking sheet under the broiler for about 5 minutes, or until the edges of the pork begin crisping up. Gently toss the pork with tongs and return to the oven for an additional 5 minutes, or until pork reaches desired crispiness.

Place pork into a bowl or serving dish and toss with some of the remaining broth from the slow cooker.

Serve in tortillas with fresh lime wedges and your favorite toppings.