Heat oven to 350°F. Spray 12x8-inch (2-quart) glass baking dish with cooking spray. In 10-inch skillet, cook ground beef over medium-high heat 5 to 7 minutes, stirring occasionally, until thoroughly cooked; drain. Stir in mixed vegetables, gravy and salt. Cook 3 to 4 minutes or until vegetables are thawed and mixture is thoroughly heated.
In baking dish, layer 3 cups of the potatoes and 1 cup of the cheese. Spoon ground beef mixture over cheese. Top with remaining potatoes. Cover with foil.
Bake 55 to 60 minutes or until bubbly. Remove foil. Sprinkle with remaining 1 cup cheese. Bake uncovered 5 minutes longer or until cheese is melted. Sprinkle with paprika before serving.