Combine all Pork Rub ingredients and massage into cubed pork.
In a large pot over medium high heat, heat 1 tbsp vegetable oil. Add onion and cook for about 3 minutes. Remove onion to a bowl.
Working in two batches, brown pork in oil left in pan from cooking onion. Remove the fist batch to the bowl with the onion. Repeat with second batch.
Add orange juice and triple sec to the pot and scrape off browned bits from bottom of pot. Add browned pork and onion back to pot. Cover with water. Reduce heat to medium low. Simmer for about 1 1/2 hours or until for tender.
Remove pork from pot, being careful to keep the cubed shape. Discard juices.
Heat a cast iron pan (or large saute pan) over medium high heat. Add 1 tbsp vegetable oil. Place cooked pork cubes in cast iron pan and sear until crispy on the outside.
Serve with flour tortillas, corn saute and tomatillo salsa.