Using a Japaneese mandolin slice the potatoes as thin as possible. Soak the potatoes in cold water to remove some of the starch from them. Drain the potatoes and dry them well. Put them into a mixing bowl and add the olive oil.
Arrange the potatoes in a single layer on a parchement lined sheet pan and sprinkle them with the salt and pepper and rosemary. Add another sheet of parchment and put another sheet pan over it sandwiching the potatoes to keep them flat. Bake in the oven at 350° degrees for 10-15 minutes until the potatoes are cooked.
Remove the potatoes from the oven and let them cool before transferring them to another container for pizza assembly.