Heat oven to 350°F. Spray 11x7-inch (2-quart) glass baking dish with cooking spray. In 1 1/2-quart saucepan, mix sauce mix and milk. Heat to boiling over medium heat, stirring constantly with wire whisk. Stir in cheese and rosemary until cheese is melted.
In baking dish, layer half of the Yukon gold potatoes, all of the sweet potato and half of the onion. Spread about half of the sauce over top. Layer with remaining potatoes and onion; cover with remaining sauce.
Cover and bake 30 minutes. Meanwhile, heat 12-inch nonstick skillet over medium-high heat. Sprinkle both sides of pork chops with peppered seasoned salt. Cook pork in skillet 4 to 5 minutes, turning once, until brown.
Place pork on potatoes. Bake uncovered 30 to 35 minutes longer or until pork is no longer pink when cut near bone and potatoes are tender.