In a medium bowl, whisk together the oil, juices, salt, cumin, oregano, red pepper flakes, pepper, and garlic.
Make slits in the pork with a knife and place the pork in the juice mixture and rub liberally all over with the oil mixture.
Place pork in the slow cooker, along with the onion and bay leaf. Poor the remaining juices from the bowl over the pork.
Cover and cook on low for 7 hours, if the meat shreds easily, it is down, if not done, cook another hour and test again. Using two forks, shred into thick chunks in the pot then use a large slotted spoon to serve it with.
Serve with mashed potatoes with some of the juice spooned over the top.
Serve in a tortilla with Cheddar cheese.
Serve with cilantro lime rice and black beans.