Combine all the ingredients in a large freezer bag and use your hands to massage the ingredients in the closed bag before placing it in the freezer. I like to thaw the bag the night before in the refrigerator so I can put the contents in the slow cooker on low in the morning. Cook on low for 5-7 hours in your slow cooker. You can also use your pressure cooker (add one cup of water) if the items are totally thawed on HIGH for 50-60 minutes. Shred the meat and serve in tortillas with Spanish rice.