Preheat oven to 400°F.

Place the sliced up potatoes in the large Ziptop bag or mixing bowl, then add in the olive oil, rosemary and garlic.

Zip the bag up, then carefully shake up the potatoes to coat them well with the oil and herbs, or stir them in the bowl until well coated. Also note that if you use more potatoes, you may need to add extra oil so keep it handy.

Spray a baking sheet with non-stick cooking spray, then carefully poor the potatoes evenly on the baking sheet.

Bake for 25-30 minutes until soft and slightly golden brown.