Preheat oven to 300
Wash meat, dry with paper towels and coat with rub on all sides.
In a large, heavy skillet with 1 tablespoon of oil or bacon grease. Brown the pork on all sides. Drain pork on papeer towels, the move to a deep roasting dish and sprinkle the remaining rub over the meat.
Brown the onions in the skillet, then remove to the roasting pan.
Deglaze skillet with 1/2 cup water, wine, or cheerwine. Scrape up the bits and pour this into the roasting pan.
Add oranges, garlic, and guajillo chilies to the roasting pan.
Add enough cheerwine to cover the meat by 1/2. Cover roasting pan with two layers of tight foil.
Braise for 3 hours, then let it rest coverd for 30 minutes.
Discard aromatics, but reserve the juice by straining it twice, then separating off the fat.
Pull the pork into chuncks. At this point the juice and meat can be refridgerated.
To serve: Allow pork to get back to room temperattuer, then add it to a heavy skillet splashing it it the juice to steam it. Make tacos or whatever.