Very important for this is the tray you use and this is also the secret. Preheat oven at max for 10-15 minutes. Cut the potatoes (I love mine larger), wash and dry them with a paper towel. Once are dried, add on them 1 TBS of Olive Oil, salt & pepper to taste and mix well. Spray the tray once (not too much as you don't want the oil to drip from the tray and make a smoky mess in your house. Put the potatoes on tray, on 1 layer only and leave them to bake (I used the middle rack). After 10 minutes, just shift them a little. Total baking time is about 30 minutes.