Remove roast and vegetables from pan, reserving juices. Pour juices into 2-quart saucepan. In small bowl, mix flour and water until smooth. Place saucepan with drippings over medium heat; gradually stir in flour mixture, cooking and stirring, until mixture comes to a full boil. Boil 1 minute, stirring constantly, until thickened. Cut roast into slices; serve with vegetables and gravy.