In a skillet, preheat 3 tablespoons of lard or oil to medium heat. After a minute, add the onions and garlic and sauté for 3-4 minutes.
Tear the chile ancho peppers into smaller pieces. Add to the skillet with the onions and garlic. Toss the chiles to cook until they begin to blister slightly and become aromatic.
Add the water and orange juice to the skillet. Bring to a boil, reduce heat and simmer for 10 minutes. Remove from heat and let cool for 10 minutes.
Transfer all skillet ingredients to the blender. Add the remaining ingredients for the sauce into blender. Blend on high until very smooth. Taste for salt. Straining the sauce is optional, but not a must.
In that same skillet, heat 3 tablespoons of pork manteca(lard) or oil to medium heat for 2 minutes. Add the shredded pork and fry, tossing as needed, until the pork begins to crisp in some spots. Mix in the reserved sauce to the pork. Continue cooking until it reduces and becomes thick. Some people like to add a little more pork lard to fry the pork in the sauce. Serve with warm tortillas, cilantro and pickled red onions.
Notes
In my opinion, the easiest way to approach recipes that require shredded meat is to cook the meat overnight in your slow cooker the day before. This way the meat will be flavorful and moist and ready to finish the recipe quickly.