Season the Pork Chops: Sprinkle both sides of the pork chops with kosher salt, black pepper, paprika, garlic powder, and onion powder. Use your fingers to rub the seasonings into the meat.
Sear the Pork Chops: Heat a large skillet over medium-high heat. Once hot, add the oil and sear the pork chops in a single layer for 2 to 3 minutes per side until golden brown. If necessary, cook in batches to avoid overcrowding. Transfer the seared pork chops to a 6-quart or larger slow cooker.
Cook the Vegetables: In the same skillet, add the sliced mushrooms and onion. Sauté over medium-high heat for 3 to 5 minutes, or until the onion is translucent. Add the minced garlic and cook for another minute, stirring constantly. Transfer the vegetables to the slow cooker, spreading them evenly over the pork chops.
Prepare the Gravy: Pour the cream of mushroom soup and beef stock into the skillet. Whisk over medium heat until smooth and combined. Pour the gravy mixture over the vegetables and pork chops in the slow cooker.
Cook: Cover the slow cooker and cook on low for 6 to 8 hours, or on high for 3 to 4 hours, until the pork chops are tender and the internal temperature reaches 145°F.
Thicken the Gravy: Remove the pork chops from the slow cooker and place them on a plate. Tent with foil to keep warm. In a small bowl, mix the cornstarch and water to create a slurry. Turn the slow cooker to high, add the slurry to the gravy, and stir well. Let the gravy cook for 5 to 10 minutes, or until thickened.
Serve: Return the pork chops to the slow cooker and spoon the thickened gravy over the top. Garnish with chopped parsley and serve over mashed potatoes, rice, or noodles.
Notes
Do not cook the pork chops over high heat when searing, as the seasonings may burn and create a bitter flavor. Medium-high heat works best.Searing is optional but highly recommended to enhance flavor and lock in moisture.If the gravy is already thick enough after cooking, you can skip the cornstarch slurry.Refrigerate: Store leftovers in an airtight container in the refrigerator for up to 3 days. Reheat in a skillet over medium-low heat, adding a splash of milk if needed to thin the gravy.Freeze: Place cooled pork chops and gravy in a freezer-safe container or bag and freeze for up to 3 months. Thaw overnight in the refrigerator before reheating on the stovetop or in the slow cooker.