Avoid potatoes that have a green tinge - they've been exposed for a prolonged period to light, developing the toxin solanine. Choose firm potatoes that haven't sprouted and aren't bruised. Don't worry about dirt or mud; it protects the potato from bruising green. Remember to select the right potatoes for the dish being prepared.
2kg of potatoes
1/4 cup of extra virgin olive oil
a couple of large sprigs of rosemary
Peel (desiree are very good for roasting) and cut them into bite-size pieces. Place them in a baking tray - use two trays if necessary so they aren't piled on top of each other - and sprinkle generously with a 1/4 cup of extra virgin olive oil. Break up a couple of large sprigs of rosemary and add them to the potatoes.
Season well with salt and toss them so they are completely coated. Roast in an oven preheated to 220C for about 35-40 minutes.
Using a spatula, carefully turn the potatoes every 15 minutes so that they crisp and go golden on all sides.