Sprinkle the pork chops with salt and pepper.
In a large skillet, heat the oil over medium-high heat. Add the pork chops and cook until browned, 4 to 5 minutes per side. Place the onions evenly over the pork chops.
In a small bowl, combine the stock, parsley, mustard and paprika, and season with salt and pepper. Pour the broth mixture over the pork chops. Return the mixture to a boil. Reduce the heat to medium and simmer for 30 minutes, stirring occasionally. Stir in the sour cream until blended and cook until heated through, 4 to 5 minutes; do not boil. Serve over hot cooked rice if using. Garnish with parsley if desired.