Season the pork shoulder generously with the sea salt and cracked black pepper.
In a small bowl, combine the dried oregano, ground cumin and olive oil to make the spice rub. Rub the mixture all over the pork shoulder.
Place the pork into the slow cooker. Add the onion, garlic, jalapeños (if using), chicken stock, adobo chilli sauce and brown sugar.
Cover and cook on high for 8 hours, or until the pork is tender and easily pulls apart.
Remove the pork and shred using two forks. Return the shredded pork to the slow cooker and stir through the cooking juices until well coated.
Serve as desired in tacos, burritos, burgers, rice bowls or with your favourite sides.
