In a small bowl, combine brown sugar through black pepper, stirring well. Season the pork with the homemade seasoning and set aside.
Set Instant Pot to Sauté. Add canola oil. Once shimmering, sear pork chunks in batches until golden brown on all sides, about 3 to 4 minutes per batch.
Add chicken stock and scrape the browned bits up with a wooden spoon. Stir in Worcestershire sauce and apple cider vinegar. Add pork chunks back to the Instant Pot.
Set Instant Pot to Manual. Seal and cook on High pressure for 40 minutes. Manually quick release pressure at the end of cooking.
Remove pork from Instant Pot to a cutting board and shred with two forks. Serve.