Fill a small saucepan with water, and boil the chiles until they are tender, for about 10 minutes. Remove the chiles from the water, and cool.
Remove the stems of the chiles, and place in the container of a blender or food processor. Add the garlic and the water, and puree until smooth. Strain the puree through a mesh colander to remove any seeds.
Pour the chile puree into an extra large mixing bowl.
Add the vinegar, salt, pepper and ground cumin, and mix well.
Add the ground pork, and mix well with the meat.
Make sure that the chile puree is evenly distributed throughout the ground pork.
Store in the refrigerator for 24 hours before using, or pack into smaller portions to store in the freezer.
To cook, place a small amount of chorizo in a pan, and brown for 5-7 minutes.
Add the cooked chorizo to your favorite recipe, or use as a topping.