rinse and pat dry the pork shoulder with a paper towel.
withe the prok marinate mix the spicees and salt together. rub the spice all over the meat. let it sit for 15-30 minutes.
Soak the mexican peppers in hot boiling water. Put a place or something heavy on top to make sure the whole pepper is soaked for 10 minutes.
break the top of the peppers off and scrape the inside clean. Throw all the peppers inside a blender with ½ cup of water. Blend until smooth.
Meanwhile, heat a pan with oil on medium high heat. place the pork shoulder on to the pan and brown all sides of the pork.
take your Instant Pot or any of your slow cooker, and set it to 'slow cook.' Set the timer for 5 hours on high temperature for the slow cooker if you have that setting. Place the pork shoulder inside the slow cooker and add all the liquids and mexican puree on top of the pork shoulder.
Close the lid and open the valve.
after 5 hours, open the lid and using two forks to break the meat up. This will allow the side of the meat to soak up all the juices. Add more salt to your taste.