Combine garlic, cocoa powder, chili powder, cumin, cayenne pepper, and Mexican oregano in a small bowl. Season with salt and black pepper, to taste, and stir to combine.
Rub pork roast with seasoning mixture on all sides and place in a 5 or 6-quart slower cooker crock. Arrange remaining solid ingredients around the pork, then pour the liquid smoke and chicken broth on top. Stir the ingredients on each side of the pork with a fork to combine.
Cover and cook on high for 4 hours, or on low for 8. Do not remove lid while cooking.
When cook time is complete, remove lid and gently pull the pork apart with two forks. Allow the pulled pork to rest in the juices for 10-15 minutes to absorb more flavor, if desired. To serve, top with shredded Mexican cheese, chopped red onion, and/or fresh cilantro. Enjoy!