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.