Bring the chicken stock and butter to a boil in a large saucepan. Stir in the couscous and remove from the heat. Cover, and let stand 10 minutes. Fluff with a fork and stir in the parsley.
Meanwhile, season the pork chops with garlic salt and pepper. Heat the olive oil in a skillet over medium-high heat. Cook the pork chops until golden brown on both sides and no longer pink in the center. Set aside.
Bring the cream of mushroom soup and milk to a simmer in the skillet used to cook the pork chops.
Serve the pork chops with the couscous and mushroom sauce.