Heat oven to 475°F. Heat 18x13-inch half-sheet pan in oven 10 minutes. Spray pan with cooking spray.
Meanwhile, in large bowl, place potatoes; spray with cooking spray. Add oil, garlic salt, pepper and sage; toss to coat. Arrange potatoes in single layer in hot pan.
Bake 15 minutes, stirring once halfway through baking, or until golden and crisp.