This is one tasty dish. The Enchilada sauce perfectly complements the pork. A good quality, store-bought chili powder may be an acceptable substitute for the freshly ground New Mexican peppers and cumin.
Place the pork butt, 1 Tbl chile powder, white vinegar, garlic and salt to taste into a zip-lock bag. Refrigerate for 6 hours, periodically shaking the bag.
Preheat oven to 240-250 degrees F. Place the oven rack on the top-most rung. Put a metal pan, half-full of water, on the floor of the oven.
Shake off the excess marinade from the steak. Bend two trussing needles into "S" shaped hooks. Push the hooks into the top of the steak. Hang it from the top grate of the oven, suspended over the water pan.
(Keep an eye on the water in the pan. It will evaporate. Fill it with more hot water, when needed.)
Roast until finished - about 3 hours. Carefully baste with excess marinade and/or white vinegar every hour.
Make the Enchilada sauce about 15 minutes before the pork is finished. Place a small sauce pan over medium heat. Melt the lard. Sprinkle in the flour. Make a blond roux, while whisking constantly. Sprinkle in 2 Tbl chile powder, cumin and garlic powder. Whisk for a few seconds. Break the roux down with water and wine. Add the tomato sauce and salt to taste. Bring to a boil then cut the heat to a slow simmer for about 10 minutes, stirring periodically.
Remove the pork steak from the oven. Take out the hooks, then coarsely slice it into thin strips against the grain. Serve in warm, flour tortillas with cheese, topped with Enchilada sauce.