Season the pork chops on both sides with garlic powder, onion powder, smoked paprika, salt, and black pepper.
Spread the sliced onion rings and mushrooms in the bottom of the slow cooker.
In a bowl, whisk together cream of mushroom soup, chicken broth, and worcestershire sauce until smooth.
Arrange the seasoned pork chops over the onions and mushrooms in the slow cooker, overlapping slightly if needed. Pour the mushroom soup mixture evenly over the top.
Cover and cook on low for 6 to 7 hours or on high for 3 to 4 hours, until the pork chops are tender and cooked through.
Carefully transfer the pork chops to a serving platter. Stir the gravy, onions, and mushrooms together in the slow cooker, then spoon the smothered gravy generously over the pork chops. Garnish with fresh parsley.