Combine seasoning ingredients in a small bowl. Coat the outside of the pork shoulder with the seasoning, reserving 2 Tbsp to be added to the soup later.
In a slow cooker, add all the vegetables, canned ingredients, 4 cups of broth and reserved seasoning. Stir to combine.
Place the pork shoulder into the slow cooker and submerge it in the broth. Add more broth as needed to fully cover the pork shoulder.
Place the lid on the slow cooker and cook on low for 9-10 hours. The pork shoulder is ready when it pulls apart easily.
When fully cooked, remove the pork shoulder and place it on a cutting board. Shred the pork using two forks and place the shredded pork back into the soup. Discard the bone if there is one.
Serve warm, and top each bowl with avocado, cilantro and/or sliced green onions, and a fresh squeeze of lime.