1. Place turnips in saucepan; cover with water. Bring to boil. Reduce heat; simmer 15 minutes or until tender. Drain; pat dry.
2. Preheat oven to 350°.
3. Arrange one third of turnips in a 2-quart baking dish coated with cooking spray; sprinkle with one third of salt and one third of pepper. Arrange half of potato over turnip. Sprinkle 6 tablespoons cheese evenly over potato. Arrange one third turnip over cheese; sprinkle with one third of salt and one third of pepper. Arrange remaining potato over turnip. Arrange remaining turnip over potato; sprinkle with remaining salt and remaining pepper. Pour broth over vegetables. Cover with foil, pressing foil down onto turnip slices. Bake at 350° for 1 hour.
4. Preheat broiler.
5. Uncover turnips; sprinkle with the remaining 6 tablespoons cheese. Broil 8 minutes or until lightly browned.