There are many varieties of potatoes. Some are better for roasting than others. Today I used cyprus potatoes, which come covered in red, sticky mud. Always make far too many potatoes, because the potato monster will enter the fridge and eat them within 24 hours, whatever you do.
Peel and wash the potatoes. Chop into roughly equal sizes, not too small. Keep them in cold water until you are ready to cook them.
Put the potatoes in a pan, cover with cold water, bring to the boil, and then simmer until they start to go slightly soft, maybe 15 minutes They should not be thoroughly cooked at this point. Drain, pour copious quantities of oil into the pan (sunflower oil is fine, olive oil or extra virgin olive oil for extra luxury), toss the potatoes around in the oil, and then empty onto an oven tray. Roast at 210C (190C in a fan oven) for 50-60 minutes.