Add potatoes, onions and mushrooms to slow cooker. Layer pork chop on top of the vegetables. Sprinkle with seasoning. Add broth, Secure lid and cook on low for 6 hours.
Remove pork chops, and most of the potatoes and mushrooms. Add cornstarch to a cup and ladle some of the broth from the slow cooker (about half a cup). Mix together into a slurry. Pour slurry into slow cooker and stir to combine. Replace lid and let thicken for 5 minutes.
Serve each pork chop with a portion of mushrooms and potatoes and ladle mushroom gravy over the top. Garnish with a sprinkle of parsley, if desired.