Pat your pork roast dry with paper towels.
Rub your pork down with your olive oil.
Then coat pork roast with salt, pepper, cumin and oregano.
Place your pork roast in your slow cooker.
Pour your orange juice over the top of your roast.
Spread onions, garlic and green chiles over the top of the roast.
Cover slow cooker and cook on low for 7-8 hours, or high for 5-6 hours.
Remove pork from slow cooker and shred with 2 forks. (Remove big pieces of fat and discard)
In a large saute pan, heat your vegetable oil over medium high heat.
Add your shredded pork and cook until the bottoms of your pork and nice and crispy.
Serve immediately.