-Use a small knife to cut each chili in half lengthwise. Pull the chilies open to remove the stem and seeds. Reserve a pinch of the seeds if you want to add more heat later.
-Add the chilies to a small saucepan with 3 cups of water, garlic, onions and spices. Bring to a boil. Remove pan from heat and let cool for about 10 minutes.
-Add chilies, garlic and onion to a blender with 2 cups of water from the saucepan. Puree until completely smooth. If you want to add more heat, add a few of the seeds to the blender and puree again until smooth.
-Place the pork shoulder into a crock pot. Pour the chili sauce over the pork and set the crock pot to low for 7-8 hours.
-Using a fork, shred the pork. It should shred very easily. Stir the sauce well with the shredded pork and serve warm.