Preheat oven to 400° and spray 2 baking sheets with non stick spray.
Wash and slice potatoes thin, place in a large mixing bowl.
Add oil and stir to coat.
Using a gallon size baggie, add grated Parmesan cheese, garlic salt and pepper. Zip shut and shake to mix.
Spoon potatoes into cheese mixture and shake to coat.
Place potatoes in a single layer on baking sheets and place in the oven
Turn once during baking.
Once browned and fork tender, approximately 40 minutes, remove from oven and enjoy with your favorite sauce, like ranch dressing.